JPH0887175A - Image forming device provided with attachable and detachable developing cartridge - Google Patents

Abstract

PURPOSE: To obtain an image forming device capable of attaching and detaching a developing cartridge while loading a photoreceptor drum cartridge without causing the interference with any other structural member at the time of attaching and detaching the developing cartridge. CONSTITUTION: This image forming device is provided with the developing cartridge attachable and detachable to from the device main body of the image forming device provided with the casing C13 with the through-window C4 for pushing out the developing unit C3, the positioning means for the developing cartridge, the developing unit energizing means for energizing the developing unit C3 so as to move toward the image carrier through the through-window C4 in a first state of the image forming device main body, and the guide means for guiding the developing cartridge in the direction of attaching and detaching in a second state of the image forming device main body.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The image forming apparatus of the present invention is an image forming apparatus provided with a detachable developing cartridge, and an image forming apparatus for assisting the attaching and detaching of the developing cartridge in cooperation with the division opening and closing of the image forming apparatus main body. Regarding the device.

[0002]

2. Description of the Related Art As an image forming apparatus having a conventional removable developing cartridge, for example, there is an image forming apparatus described in Japanese Patent Laid-Open No. 1-241402. In the developing cartridge of this image forming apparatus, as shown in FIG. 12, a developing device C3 including a developing sleeve, a stirring roller, and a drive gear group for driving each of them is mounted on the developing cartridge C. The developing cartridge C is provided with a spring that biases the developing device C3 toward the photosensitive drum. At both ends of the developing sleeve, attached rollers having an outer diameter that is larger than the outer diameter of the developing sleeve by a certain amount are provided. The casing C13 of the developing cartridge supports the developing device C3 and is also a restricting member that limits the moving direction of the developing device C3 to the photosensitive drum direction. In addition, the photosensitive drum 10T is also detachably configured as a drum cartridge.

In such an image forming apparatus, when the developing cartridge is mounted in the main body of the image forming apparatus, the casing C13 of the developing cartridge is positioned with respect to the image forming apparatus, and the developing device C3 causes the photosensitive drum 10 to move by the spring S.
It is pressed in the direction of T. In this state, the contact rollers on both ends of the developing sleeve hit the photosensitive drum 10T of the drum cartridge, and the distance between the photosensitive drum 10T and the developing sleeve is determined to be an interval suitable for two-component jumping development.

On the other hand, a drive gear train for driving the developing device of the conventional image forming apparatus shown in FIG. 13 is provided in a drive gear group provided in the developing cartridge casing and a main body side drive gear group on the image forming apparatus main body side. Separately, the developing sleeve is driven by using the motor of the main body of the image forming apparatus as a drive source. In addition, the drive gear train, when the drum cartridge is attached and detached with the developing cartridge installed,
Gears engage / disengage according to attachment / detachment. That is, when the drum cartridge is mounted while the developing cartridge is mounted, the abutting roller comes into contact with the photosensitive drum 10T and the developing device C3 retracts against the urging force of the spring S. And the drive gear 201 on the main body side mesh with each other. Further, when the drum cartridge is pulled out, the developing device C3 advances due to the urging force of the spring, so that the engagement between the cartridge side drive gear 200 and the main body side drive gear 201 is released.

However, in the image forming apparatus as disclosed in Japanese Patent Laid-Open No. 1-241402, the mounting and demounting of the developing cartridge C is restricted in the state where the drum cartridge is mounted. This is because the developing device C3 is constantly urged toward the photoconductor drum 10T by the spring, so that the photoconductor drum 10T and the developing sleeve are close to each other when the drum cartridge is mounted. Drum 10
Since it is in contact with T, it is for avoiding contact and damage due to the detaching operation of the photosensitive drum 10T, the developing sleeve and the like.
Further, the drive gear train does not engage / disengage in the mounted state of the drum cartridge because the mounting / detachment of the developing cartridge is restricted in the mounted state of the drum cartridge.

In addition to this image forming apparatus, there is an image forming apparatus having a drum cartridge which moves a supporting shaft of a photosensitive drum in cooperation with divisional opening and closing of the image forming apparatus main body. However, in this image forming apparatus, the structure of the cartridge including the supporting shaft of the drum is complicated, and the positional relationship with the charger, the cleaning device, and the like arranged around the drum on the photosensitive member is not stable.

Further, the developing cartridge used in the image forming apparatus has a complicated structure because it has means for urging the developing device to the photosensitive member.

[0008]

SUMMARY OF THE INVENTION That is, the present invention is an image forming apparatus having a developing cartridge, wherein the drum cartridge and the developing cartridge are attached to the developing cartridge regardless of whether the developing cartridge is attached or not. An object of the present invention is to obtain an image forming apparatus which can be attached and detached without damaging the constituent members of the drum cartridge regardless of whether the drum cartridge is attached or not. Another object is to obtain an image forming apparatus having a developing cartridge with a simple structure.

[0009]

The above object can be achieved by the following means. That is, the image forming apparatus according to claim 1 has a casing having a supporting means for supporting the developing device so as to be contactable and separable with respect to the image carrier, a positioning means for positioning the main body of the image forming apparatus, and a casing. A developing cartridge that is detachable from the apparatus main body of the apparatus; positioning engaging means that engages with the positioning means when the developing cartridge is mounted on the image forming apparatus main body; Developing device urging means for urging the developing device through the opening so as to move the developing device in the direction of the image carrier, and a guide for guiding the developing cartridge in the attachment / detachment direction in the second state of the image forming apparatus main body. And means.

An image forming apparatus according to a fifth aspect of the present invention includes a developing cartridge that has a developing device and is detachable from the main body of the image forming device, and a support that supports the developing device so that it can be contacted and separated from the image carrier. And a driving unit that is movably supported in the axial direction by a driving shaft that rotates integrally with the driving unit and that transmits the driving force to the developing unit; and the driving unit that moves the driving unit in the axial direction and transmits the driving force to the developing unit. And a drive biasing means supported by the drive shaft and moving the drive means in the axial direction against the biasing force of the drive biasing means. It is characterized by having a drive canceling means for canceling the drive transmission of.

According to a ninth aspect of the present invention, there is provided an image forming apparatus having a casing having a supporting means for supporting the developing device so that the developing device can be brought into contact with and separating from the image carrier, a positioning means for positioning the main body of the image forming apparatus, and an opening. A developing cartridge that is detachable from the apparatus body of the image forming apparatus, a positioning engagement means that engages with the positioning means when the developing cartridge is mounted in the image forming apparatus body, and a first state of the image forming apparatus body. And a developing device urging means that urges the developing device through the opening so as to move the developing device toward the image carrier, and guides the developing cartridge in the attachment / detachment direction in the second state of the image forming apparatus main body. Guide means for driving, a driving means that is movably supported in the axial direction by a driving shaft that rotates integrally, and that transmits a driving force to the developing device, and the driving means that moves the driving means in the axial direction. An urging force for displacing the driving force to the device and a driving urging means supported by the drive shaft, and the driving means is moved in the axial direction against the urging force of the driving urging means. And a drive releasing means for releasing drive transmission of the developing device.

The first state is a state in which an image can be formed, and the second state is a state in which the developing cartridge can be attached and detached.

[0013]

According to the above construction, the image forming apparatus according to the invention of claim 1 is provided with a positioning means for supporting the developing device with respect to the image carrier and a positioning means for the main body of the image forming device and an opening. A developing cartridge having a casing having a portion and detachable from the apparatus main body of the image forming apparatus; positioning engaging means that engages with the positioning means when the developing cartridge is mounted in the image forming apparatus main body; In a second state of the image forming apparatus main body, a developing device urging means for urging the developing device through the opening so as to move the developing device toward the image carrier in the first state of the image forming apparatus main body. Since the drum cartridge and the developing cartridge have guide means for guiding the developing cartridge in the attaching / detaching direction, the drum cartridge and the developing cartridge can be attached / detached regardless of whether or not the developing cartridge is attached. Regardless of the presence or absence of the mounting of the drum cartridge during the image cartridge detachable and detachable without damaged the mutual constituent members both.
In addition, it is possible to use a developing cartridge having a simple structure that does not have a biasing means inside the developing cartridge casing.

Further, in the image forming apparatus according to the invention of claim 5, a developing cartridge having a developing device and detachable from the main body of the image forming device, and the developing device can be brought into contact with and separated from the image carrier. A supporting unit that supports the driving unit, a driving unit that is movably supported in the axial direction by a driving shaft that rotates integrally, and that transmits a driving force to the developing unit, and the developing unit that moves the driving unit in the axial direction. A biasing force for displacing the driving force to a position where the driving force is transmitted to the driving shaft, the driving biasing means being supported by the driving shaft, and the driving means being moved in the axial direction against the biasing force of the driving biasing means. Since the drive canceling means for canceling the drive transmission of the developing device is provided, the defect of the drive transmission due to the attachment / detachment of the developing cartridge is eliminated.
In addition, since the drive can be released even with the drum cartridge installed, the drum cartridge and the developing cartridge can be installed or removed regardless of whether the developing cartridge is installed or not. It became detachable regardless of the type.

An image forming apparatus according to a ninth aspect of the present invention has a casing having a support means for supporting the developing device so that the developing device can be brought into contact with and separated from the image carrier, a positioning means for the main body of the image forming apparatus, and an opening. A developing cartridge that is detachable from the apparatus body of the image forming apparatus, a positioning engagement means that engages with the positioning means when the developing cartridge is mounted in the image forming apparatus body, and a first state of the image forming apparatus body. And a developing device urging means that urges the developing device through the opening so as to move the developing device toward the image carrier, and guides the developing cartridge in the attachment / detachment direction in the second state of the image forming apparatus main body. Guide means for driving, a driving means that is movably supported in the axial direction by a driving shaft that rotates integrally, and that transmits a driving force to the developing device, and the driving means that moves the driving means in the axial direction. And a drive biasing means supported by the drive shaft for moving the drive means in the axial direction against the biasing force of the biasing means. Since the drum cartridge and the developing cartridge have the driving releasing means for releasing the drive transmission of the developing device, the drum cartridge and the developing cartridge are not attached to the drum cartridge regardless of whether the developing cartridge is attached or not. An object of the present invention is to obtain an image forming apparatus which can be attached and detached without damaging the constituent members of each other, regardless of whether the image forming apparatus is attached or not. Drive transmission failure due to attachment / detachment of developer cartridge has disappeared. In addition, since the drive can be released even with the drum cartridge installed, the drum cartridge and the developing cartridge can be installed or removed regardless of whether the developing cartridge is installed or not. Irrespective of the fact, the drive transmission was eliminated even after the attachment / detachment. In addition, it is possible to use a developing cartridge having a simple structure in which the developing cartridge casing has no biasing means.

[0016]

Embodiments of the present invention will be described below with reference to FIGS.

FIG. 1 is an overall configuration diagram of the image forming apparatus. As shown in the figure, the photoconductor drum 10T as an image carrier having the OPC photosensitive layer coated on its surface is driven and rotated in one direction (clockwise in the figure), and the charge is erased by the charge eliminator 11T to charge the previous print. After being removed, the charger 12T
As a result, the peripheral surface is uniformly charged, and a new print is prepared. After this uniform charging, the image exposure means 13T performs image exposure based on the image signal. The image exposure unit 13T rotates and scans the laser beam emitted from the laser beam by the rotary polygon mirror 131T, passes through the fθ lens 132T, and the reflection mirror 133.
Precharged photoconductor drum 1 whose optical path is bent by T
A latent image is formed on the surface of the photoconductor drum 10T by being projected onto the peripheral surface of 0T.

The periphery of the photosensitive drum 10T is filled with a developer composed of a mixture of yellow (Y), magenta (M), cyan (C) and black (K) toners and a magnetic carrier. The developing devices C3Y, C3M, C3C, C3K are provided, and first, the development of the first color is carried out by the developing sleeve 141T which contains a magnet and rotates. The developer is regulated to a predetermined thickness on the developing sleeve 141T by the layer forming rod and is conveyed to the developing area. Photoconductor drum 10
AC bias voltage and D between T and developing sleeve 141T
The C bias voltage is superimposed and applied, and visualized by a known method.

After the development of the first color is completed in this way, the image forming process of the second color (magenta) is started, and the photosensitive drum 10T is uniformly charged again, and the third color (cyan), 4
An image forming process similar to that for the second color is performed for the color (black), and a total of four colors are developed on the photosensitive drum 10.

On the other hand, the paper feeding mechanism 22 by the paper feeding cassette 21T.
The recording paper, which is the transfer material fed by T, is the transfer belt 31.
The transfer belt device 24T in which T is stretched is used as a photosensitive drum.
Nip 35T formed between 10T and transfer belt 31T
The multicolor image on the peripheral surface of the photosensitive drum 10T is collectively transferred onto a recording sheet. Here, a high voltage is applied to the shaft 32aT of the upstream holding roller 32T of the transfer belt 31T,
The conductive brush is grounded at a position facing the shaft 32aT with the transfer belt 31T interposed therebetween, and the conductive brush enters the transfer area while being attracted to the transfer belt 31T by the electric charges injected into the fed recording paper. The recording paper separated from the photosensitive drum is transferred to the transfer belt 31 while being neutralized by using the shaft 33bT of the holding roller 33T on the downstream side that stretches the transfer belt 31T as a counter electrode.
Separate from T. The toner attached to the transfer belt is removed by the cleaning blade 37T. The transfer belt is separated from the photosensitive drum about the shaft 33bT of the holding roller 33T on the downstream side during the formation of the multicolor image.

The recording paper separated from the transfer belt device 24T is conveyed to a fixing device 23T composed of two pressure rollers having a heater inside at least one roller,
By applying heat and pressure between the two pressure-bonding rollers, the adhered toner is melted, fixed on the recording paper, and then discharged to the outside of the apparatus.

The toner remaining on the photosensitive drum after the transfer is destaticized by the destaticizer 15T, and then the cleaning device 16T.
When the cleaning blade 16a is in contact with the photosensitive drum 10T, it is scraped off into the cleaning device, discharged by a screw or the like, and stored in the recovery box. The photoconductor drum from which the residual toner has been removed by the cleaning device 16T is neutralized by the static elimination lamp 11T, and then uniformly charged by the charger 12, and the next image forming cycle is started. Further, if the recording paper is wound around the photosensitive drum 10T without being separated from the transfer belt 31T and gets into the cleaning portion, the recording paper cannot be taken out, and thus the cleaning function cannot be sufficiently performed, or May damage the cleaning blade, the electrode wire, or reduce the function of the electrode and the static elimination lamp. Therefore, the jam sensor 36T that detects the winding of the recording paper is located near the static eliminator. It is installed. Further, a developing cartridge described later has at least one developing device including the developing devices C3Y, C3M, C3C and C3K shown in FIG. 1, and is a cartridge that is detachable from the main body of the image forming apparatus. Further, the drum cartridge is a cartridge that is detachable from the main body of the image forming apparatus including the photosensitive drum 10T shown in FIG.

FIG. 2 is an external perspective view of the developing cartridge. 2A shows a color cartridge, and FIG.
(B) shows a black cartridge.

In FIG. 2A, the color cartridge C1 is a developing device C3Y, C3M, C3C that develops a toner image on the photosensitive drum 10T with yellow, magenta, and cyan developers, respectively.
Is movably supported by a casing C13. Further, the casing C13 is a developing device supporting surface which is a sliding surface with respect to the developing devices C3Y, C3M, C3C, and limits the moving direction of the developing devices C3Y, C3M, C3C to reciprocating movement toward the photoconductor drum 10T. The developing device protrusion C9 is fitted to the developing device guide C10, and each developing device C3Y, C3
The movement range of M and C3C is limited. Developing devices C3Y, C3M, C3C
Is pressed in the direction of the photoconductor drum 10T by the developing device urging means of the present invention which urges the casing C13 from the outside through the through window C4 related to the opening of the present invention. When the developing devices C3Y, C3M, and C3C are pressed against the photoconductor drum 10T, the contact roller C7 is provided with the photoconductor drum 10T and the developing sleeve 14.
The 1T interval is maintained at an interval suitable for development. However, Figure 2
In the color cartridge C1 of (A), the abutting roller C7 is arranged at a visible position, so that it is shown in FIG. 2 (B).
Gears G41, G42, G43 of the developing devices C3Y, C3M, C3C are developing device driving gears and are fixed coaxially with the developing device driving belt C6. Gears of a drive system on the main body side, which are gears by moving gears G41A, G42A, G43A (described later) according to the drive means of the present invention.
When meshed with G41, G42, G43, the driving force for rotating the developing sleeve 141T of each of the developing devices C3Y, C3M, C3C, C3K, stirring blades, etc., can be transmitted. On the other hand, when the gears G41A, G42A, G43A are moved by the drive releasing means of the present invention to release the mesh, the transmission of the driving force is temporarily cut off. The cartridge positioning hole C8 is a casing when the color cartridge C1 is mounted as shown in FIG.
A positioning hole for positioning C13, which engages with a positioning pin of the image forming apparatus main body. The developing cartridge handle C11 is a handle held by the operator when the color cartridge C1 is attached to or detached from the main body of the image forming apparatus. The developing cartridge fishing hook C12 is a fishing hook held by the operator when attaching or detaching the color cartridge.

In FIG. 2B, the black cartridge C2 is
Like the color cartridge C1, the developing device C3 is held so as to reciprocate in the direction of the photosensitive drum 10T. However, the black cartridge C2 is different from the color cartridge C1 in that it holds a developing device C3K for developing with a black developer. The gear according to the driving means of the present invention is G44A, and the developing device drive gear is G44. The other components are the same as those of the color cartridge C1. The same components as those of the color cartridge C1 are designated by the same reference numerals. The contact roller C7 is the contact roller previously described in FIG. 2 (A).

Next, the structures of the developing device urging mechanism 60 having the developing device urging means of the present invention and the driving gear urging releasing mechanism 70 including the driving releasing means of the present invention will be described with reference to FIG.

FIG. 3 is a perspective view showing the structures of the developing device urging mechanism 60 and the drive gear urging releasing mechanism 70. Note that FIG. 3 shows the closed state of the upper body 21.

First, the developing device urging mechanism 60 will be described.

The main body frame 50 is the upper main body of the image forming apparatus.
It is provided inside 21.

The main body frame 50 has a main body penetrating window 51, and has a color cartridge C1 and a black cartridge C2.
Body through window 51 and through window when the
C4 forms a communicating window. The leaf springs 61Y, 61M, 61C, 61K relate to the developing device urging means of the present invention, and the color cartridge C1 or the black cartridge C2 is passed through the communicating window.
Is in a position to urge. The leaf spring 61Y is the developing device C3Y, the leaf spring 61M is the developing device C3M, and the leaf spring 61C is the developing device C3C.
61K energizes each of the developing devices C3K.

Further, in the present embodiment, the main body frame 50 also serves as a guide member for guiding the color cartridge C1 and the black cartridge C2 in the attaching / detaching direction. The main body frame 50 is provided with rails (not shown), a bottom plate support plate of the casing C13, and the like.

The leaf spring drive cam 62 includes the leaf springs 61Y, 61M, 61C,
This is a cam for driving 61K, and the leaf springs 61Y, 61M, 61C, 61K are hooked by the leaf spring engaging claws 63. Cam fixed shaft 64
Is fixed to a fixing member (not shown) of the upper body 21 and determines the rotation axis of the leaf spring drive cam 62. Cam fitting 65
Is fixed to the connecting plate 80 and is slidably engaged with the plate spring drive cam 62. That is, the connecting plate 80 is indicated by an arrow A in the figure.
When moved in the direction of, the leaf spring drive cam 62 rotates in the direction of arrow B in the figure. Therefore, in the leaf springs 61Y, 61M, 61C, 61K, the portions hooked by the leaf spring engaging claws 63 move in the direction of arrow B. As a result, the leaf springs 61Y, 61M, 61C, 61K are connected to the developing devices C3Y, C3.
It is displaced to a position retracted from M, C3C, C3K and retracted from the communicating window. The connecting plate 80 moves in the direction A in the figure when the upper body 21 is opened. In this embodiment, since two developing device urging mechanisms 60 are provided, the moving direction of each developing device C3Y, C3M, C3C, C3K should be accurate when urging each developing device.

Next, the drive gear bias release mechanism 70 will be described.

The main body frame 50 has steps at portions corresponding to the developing devices C3M and C3C of the color cartridge C1. This is because the developing devices C3Y, C3M, C3C, C3K having the same or substantially the same size are arranged on the cylindrical photosensitive drum 10T.
The gear pressing plate 71 relates to the drive releasing means of the present invention, and is a plate-like member having a shape corresponding to the step of the main body frame 50. The gear pressing plate driving plate 72 is mounted on the body frame 50 by a driving plate fixing pin 74.
It is rotatably supported by. Gear pressing plate Drive plate
The gear pressing plate side pin 73 slidably engages with the gear pressing plate 71, and the coupling plate side pin 75 slidably engages with the coupling plate 80.

When the connecting plate 80 moves in the direction of the arrow A in the drawing, the gear pressing plate drive plate 72 rotates in the direction of the arrow C in the drawing with the drive plate fixing pin 74 as an axis, so that the gear pressing plate 71 in the drawing. Move in the direction of arrow D. At this time, since the gear pressing plate 71 has a shape corresponding to the step of the main body frame 50, the gear pressing plate 71 moves using the main body frame 50 as a guide. Further, the main body frame 50 and the gear pressing plate 71 are locked by the locking claws 52 so as not to separate from each other.

The gear fitting portion 78 is shaped so as to avoid the shaft 45A of the gear G41A and press only the gear G41A when the gear pressing plate 71 presses the gear G41A described later. The operation when the gear G41A is pressed by the gear pressing plate 71 will be described later in detail. Generally, when the gear G41A is pressed by the gear pressing plate 71, the gear G41A is displaced and the meshing with the gear G41 is released.

The connecting plate 80 is rotatably engaged with the reciprocating plate 81 and the connecting plate side pin 82. The reciprocating plate 81 is rotatably held around the connecting plate fixing pin 83 as an axis. The connecting plate fixing pin 83 is fixed to a main body fixing member (not shown). The connecting plate joint pin 84 is fixed to the reciprocating plate 81, and when the connecting plate joint pin 84 is pulled in the direction of arrow E in the figure, the connecting plate 80 moves in the direction of arrow A in the figure. As a result, the developing device urging mechanism 60 releases the urging by the leaf spring 61, and the drive gear urging releasing mechanism 70 releases the urging of the gear G41A.

Next, the operation of the developing device urging mechanism 60 will be described with reference to FIG.

FIG. 4 is a top view of the developing device urging mechanism 60.
Here, the operation of the developing device urging mechanism 60 for the developing device C3K will be described, but the same applies to the other developing devices C3Y, C3M, C3C. FIG. 4A shows the closed state of the upper main body 21, and the developing device C3K is in a developable state. FIG. 4B shows a state in which the upper main body 21 is opened, and the developing device C3K is in a non-developable state. That is, as shown in FIG. 4 (A), the upper body
When 21 is closed, the reciprocating plate 81 moves in the direction opposite to the arrow A in the figure by the action of the upper and lower body connecting plates 85, and as a result, the plate spring is moved via the connecting plate 80 and the plate spring drive cam 62. 61K is in the state of pressing the developing device C3K. At this time leaf spring 61K
Penetrates the through window C4 of the casing C13 and the main body through window 51 of the main body frame 50 to press the developing device C3K toward the photoconductor drum 10T.

When the upper main body 21 is open as shown in FIG. 4B, the reciprocating plate 81 is rotated in the direction of arrow E in FIG. Moves in the direction opposite to the closing direction, that is, in the direction of arrow A in FIG. 4 (A), and as a result, the leaf spring 61K also moves in the opposite direction to the closing state via the connecting plate 80 and the leaf spring drive cam 62. Therefore, the leaf spring 61K is the developing device C.
Retreat from 3K and also through window C4. Further, as shown in FIG. 9, the upper main body 21 is in an inclined state when it is in an open state. Therefore, when the biasing force of the plate spring 61K is released, the developing device C3K retracts from the photoconductor drum 10T by its own weight.

FIG. 5 is a perspective view showing a drive system of the developing device and the image forming apparatus. The developing devices C3Y, C3M, C3C, C3K are configured so that the respective developing devices function by the rotation of gears G41, G42, G43, G44 provided therein.

M1 is a developing driving motor, M2 is a cam driving motor, an AC motor is used as the motor M1, and a pulse motor is used as the motor M2. The gear train for developing drive rotated by the motor M1 will be described. The gear G11 attached to the motor M1 is the gears G14, G15, G16, G17, G1.
8, G19, G20, G21 mesh with the series. Among them, the gears G14, G16, G18, G20 are idle gears, and are provided to make the developing device drive directions the same.

A gear G41A according to the driving means of the present invention is coaxial with the gear G15, and a spring clutch S41 is provided between the gear G15 and the gear G41A for switching between driving and disengaging. Gears G17, G42A and spring clutch S42;
Gears G19, G43A and spring clutch S43; Gears G21, G44A
And the spring clutch S44 have the same relationship.

Next, description will be made with reference to the partial configuration diagram of the drive system shown in FIG. Hereinafter, the operation of the drive system of the developing device C3Y of the color cartridge C1 will be mainly described, but other developing devices C3M, C3C, C3
The operation of the K drive system is similar.

FIG. 6A shows the drive system with the gear pressing plate 71 retracted. The shaft 45Y relates to the drive shaft of the present invention, and the shaft 45Y supports a gear G41A at one end thereof so as to be movable in the axial direction. The coil spring S45Y is inserted through the shaft 45Y and has one end arranged so as to apply a biasing force to the gear G41A via the pressing plate P45Y, and the other end fixed to a ring R45Y provided between the gear G41A and the gear G15. Body side frame
Pressing 51. The shaft 45M and the coil spring S45M described in FIG. 5 are between the gear G17 and the gear G42A, the shaft 45C and the coil spring S45C are between the gear G19 and the gear G43A, and the shaft 45K and the coil spring are shown.
S45K is provided between gear G21 and gear G44A, respectively.

FIG. 6B shows the drive system when the gear pressing plate 71 is urged. The gear pressing plate 71 is a gear fitting portion.
Gear G41A with coil spring S45Y so that shaft 45Y fits into 78Y.
Pressing against. As shown in FIG. 6 (C), the cross-sectional shape of the shaft 45Y is not a circular shape, but is a circular cutout part.
Has 45D. The gear G41A is also provided with a through hole having the same shape as the cross-sectional shape of the shaft 45Y concentrically with the rotating shaft. The pressing plate P45Y and the ring R45Y also have similar through holes. Since the shaft 45Y is inserted through the through hole of the gear G41A, the shaft 4
When 5Y rotates, the rotation is transmitted to gear G41A. The shaft 45Y is inserted through the pressing plate P45A and the ring R45Y, and the shaft 4
It rotates with the rotation of 5Y. When the gear G41A is pressed by the gear pressing plate 71 as described with reference to FIG.
When the pressing force is released, the coil spring moves along
Move to the end of axis 45Y by S45Y. Gear G41Y
Is normally located at the end of the shaft 45Y because it is biased by the coil spring S45Y. The end of the shaft 45Y has a flange so that the gear G41A does not come off due to the bias of the coil spring S45Y. These configurations are shaft 45M, coil spring S45M, gear G42.
The same configuration is applied between A, between the shaft 45C, the coil spring S45C, and the gear G42A, and between the shaft 45K, the coil spring S45K, and the gear G44A.

FIG. 6C is a partial block diagram of the gear G41A. The tooth surface of the tooth G41T of the gear G41A is inclined as illustrated. Further, the gear G41 of the developing device C3Y has the same configuration, and the gear G41 and the gear G41A are arranged so that the tapers face each other. Further, the shaft 45Y has a play in the rotation direction, and the gear G421 can rotate slightly even when the driving force is not transmitted. Therefore, when the gear G41A moves, the gear G41T and the gear G41A
Gear G41A and gear G41
Mesh smoothly. In the figure, the tooth G4 is
A part is written without writing 1T.

In FIG. 5, the gear G41A meshes with the gear G41 when the developing devices C3Y are in the developing state. Similarly gear G42
A and a gear G42; a gear G43A and a gear G43; a gear G44A and a gear 44 mesh with each other and are connected to the developing devices C3M, C3C and C3K, respectively.

Looking at the cam drive, the gears G32, G33, G3
4, G35, G36, G37, G38 mesh with the series, and the gear G35 between them meshes with the gear G31 attached to the shaft of the motor M2.

A cam C41 is coaxially attached to the gear G32. The cam C41 is a cam that faces the spring clutch S41 and switches the connection. Gear G34 and cam C42; gear G3
6 and the cam C43; the gear G38 and the cam C44; have a coaxial relationship with each other, and the connection is switched in opposition to the spring clutches S42, S43, S44.

The cams C41, C42, C43, C44 are attached with a phase relationship of 72 ° with respect to each other. That is, it is divided into five equal parts and arranged so that the protruding portions C01 are located in the four directions.

In the developing drive device having the above-mentioned structure, even if the motor 1 is turned on during copying, the spring clutch S4
1 to S44 do not transmit power, so the developing devices C3Y, C3M,
Neither C3C nor C3K works. Upon development, the control unit drives the motor M2 to rotate the cam in the direction of the arrow (clockwise) directed at 72 ° and stops at that position. Cam on this
C41 contacts the spring clutch S41, and power is transmitted to the developing device C3Y. Then, by further rotating the 72 ° cam in the direction of the arrow and stopping at that position, the power transmission to the developing device C3Y stops, and instead the cam C42 abuts the spring clutch S42 and the power transmission to the developing device C3M is performed. It Similarly, by further rotating the cam by 72 ° in the direction of the arrow and stopping it, the cam C43 comes into contact with the spring clutch S43, and the developing device C3M is replaced by the developing device.
C3C works. Further, the operation is switched to the developing device C3K by rotating the 72 ° cam in the direction of the arrow.

FIG. 7 is a top view showing the operation of the drive gear bias release mechanism 70. 7A shows a state in which the image forming apparatus is closed by the split opening / closing means, and FIG. 7B shows a state in which the image forming apparatus is opened. In addition, the operation of the drive gear bias release mechanism 70 to the developing device C3Y will be described.
The operation for 3M, C3C, and C3K is similar.

FIG. 7A shows a state in which the upper main body 21 is closed. As described with reference to FIG. 4 (A), the upper and lower body connecting plates 85 act and the leaf spring 61 urges the developing device C3Y. At this time, the contact roller C7 of the developing device C3Y is the photosensitive drum 1
It hits 0T and is in a developable state. The drive gear bias release mechanism 70 is in a position where the gear pressing plate 71 is released from the gear G41 via the reciprocating plate 81, the connecting plate 80, and the gear pressing plate driving plate 72 by the action of the upper and lower body connecting plates 85.
At this time, the gear G41 is in a position where it meshes with the gear G41A because it is biased by the coil spring S41Y according to the driving biasing means of the present invention. Therefore, when the drive force on the main body side is transmitted from the shaft 45Y to the gear G41A, the drive force is transmitted to the gear G41,
The developing sleeve 141T, the stirring blade, and the like included in the developing device of the developing device C3Y operate.

In FIG. 7B, since the upper main body is opened, the leaf spring 61 is retracted from the developing device C3 as described with reference to FIG. 4B, and the drive releasing means presses the gear G41A to attach it. The power is off. That is, when the upper main body 21 is opened, the gear pressing plate 71 of the drive gear bias release mechanism 70 moves the gear G41 in the direction of arrow F in the figure against the biasing force of the coil spring S45Y. The gear G41A concerned also moves in the direction of arrow F along the shaft 45Y, and the meshing with the gear G41 is released. Further, since the engagement is released at this time, the interference between the drive systems does not occur even if the developing cartridge is pulled out. That is, according to the configuration of this embodiment, the transmission mechanism of the drive system on the main body side and the drive system on the developing cartridge side is released without pulling out the drum cartridge, and even if the developing cartridge is pulled out while the drum cartridge is mounted, the drive mechanism is driven. Transmission failure of the system does not occur. That is, in the present embodiment, the gear G41A according to the drive means of the present invention is urged by the coil spring 61Y according to the drive urging means of the present invention to transmit the drive, and the gear pressing plate 71 according to the drive release means of the present invention. Coil spring 61
The gear G41A is configured to move along the shaft 45Y against the urging force of Y to release the drive.

On the other hand, when the developing cartridge is loaded, the upper main body 21 is open and in the inclined position. When the color cartridge C1 or the black cartridge C2 is attached to the upper main body 21 in this state, the developing device slides inside the casing C13 by its own weight and separates from the photosensitive drum 10T as shown in FIG. Casing C1
It comes into contact with 3. At this time, the gear G41A moves along the shaft 45Y in the direction opposite to the arrow F in FIG.
It interferes with 1. Therefore, in the image forming apparatus according to the present exemplary embodiment, the developing device is attached to the photosensitive drum along with the closing operation of the upper main body.
Push in the direction of 10T. Therefore, the gear G41 moves to a position where the gear G41A does not interfere with the movement of the gear G41A in the direction of the shaft 45Y. At the same time, since the drive releasing means is also retracted, the gear G41A returns to the position where the driving force can be transmitted by the biasing force of the coil spring S45Y, and the gear G41A and the gear G41 mesh with each other. Therefore, when the upper main body 21 is closed after the developing cartridge is mounted,
The state becomes (A). As described above, in this embodiment, since the developing device urging mechanism 60 and the drive gear urging release mechanism 70 are interlocked with each other in association with the movement of the connecting plate 80 by the upper and lower body connecting plates 85, the developing cartridge can be securely mounted. It will be possible.

Next, with reference to FIGS. 8 and 9, the operation of each part when the main body of the image forming apparatus of the present invention is divided and opened / closed will be described.

FIG. 8 is a partial block diagram of the image forming apparatus shown in FIG. Referring to FIG. 8, the developing device urging mechanism 60 and the driving gear urging releasing mechanism of the present invention with the upper body 21 closed.
Explain 70.

First, the developing device urging mechanism 60 will be described. The leaf springs 61Y, 61M, 61C, 61K relate to the urging means of the present invention, and push out the developing devices C3Y, C3M, C3C, C3K of the color cartridge C1 or the black cartridge C2 toward the photoconductor drum 10T. It is a spring that urges against. Leaf springs 61Y, 61M, 61C, 61
K, corresponds to push out the developing devices C3Y, C3M, C3C, C3K separately.

The leaf spring drive cam 62 is engaged with each leaf spring 61Y, M, C, K by a leaf spring engaging claw 63. Leaf spring drive cam
62 is a cam fixing shaft 64 supported by a main body fixing member (not shown)
Rotate around. In the figure, the cam fixed shaft 64 is a reciprocating plate.
Partly hidden in the shadow of 81. The cam joint 65 is a pin that slidably connects the connecting plate 80 and the plate spring drive cam 62,
It is fixed to the connecting plate 80. FIG. 8 shows a state in which the upper main body is closed. At this time, in the developing device urging mechanism 60, each leaf spring 61Y, 61M, 61C, 61K passes through the through window C4 and each developing device C3.
Displace Y, C3M, C3C, C3K to the pushing position. Further, when the color cartridge C1 and the black cartridge C2 are mounted as shown and the photoconductor drum 10T and the abutment roller C7 come into contact with each other, the developing state becomes possible.

The upper / lower body connecting plate 85 is a connecting plate for interlocking the opening / closing operation of the upper / lower body with the operations of the developing device urging mechanism 60 and the driving gear urging releasing mechanism 70. Grooves are cut in the upper and lower body connecting plates 85, and connecting plate joint pins 84, fixing pins 86, 8
7, 88 are fitted. The fixing pins 86 and 87 are fixed to the upper body, and the fixing pin 88 is fixed to the lower body.

FIG. 9 is a partial block diagram of the image forming apparatus with the upper main body 21 opened. The developing device urging mechanism 60 and the drive gear urging releasing mechanism 70 of the present invention with the upper body opened.
Will be explained.

The lower main body 22 is a paper feed cassette of the image forming apparatus.
21T, fixing device 23T, etc. on the lower body, upper body 21
Is an upper main body including the image exposing means 13T, the drum cartridge, the color cartridge C1, the black cartridge C2 and the like. The shaft 2 is a shaft that allows the upper body 21 and the lower body 22 to freely rotate. The drum cartridge 100 is a unit including at least an image carrier. When the upper main body 21 is opened, the distance between the upper main body 21 and the lower main body 22 widens, so that the upper and lower main body connecting plates 85 are moved to the lower body 22 relative to the upper main body 21 by the action of the fixing pin 88. Displace. At this time, the fixing pin 86 is fixed to the upper body 21,
Since the connecting plate 80 of the connecting plate joint pin 84 is rotatable about the connecting plate fixing pin 83, the connecting plate joint pin 84 moves toward the fixing pin 86 along the groove of the upper and lower body connecting plates 85.
When the connecting plate joint pin 84 moves, the connecting plate 80 moves to the front side in the figure, and the developing device urging mechanism 60 and the drive gear urging releasing mechanism 70 are moved.
To operate. That is, the leaf springs 6161Y, 61M, 61C, 61K retract from the developing devices C3Y, C3M, C3C, C3K and stop the extrusion through the through window C4. Further, the drive gear bias release mechanism 70 moves the gear pressing plate 71 to release the bias of the drive bias means.

Next, referring to FIG. 11, the upper main body 21, the lower main body 22, and the drum cartridge 10 will be described with reference to a schematic view in which the upper main body 21 is opened and rotated about 45 degrees around the support shaft 2.
The configuration of 0 will be described.

A paper feed cassette 21T, a paper feed mechanism 22T, a transfer device 24T and a fixing device 23T are mounted on the lower main body 22, and an image exposing means 13, a color cartridge C1, a black cartridge C2 and a toner hopper 40 are mounted on the upper main body 21. Etc. are incorporated, and further, photoconductor drum 10T, PCL 11T, charger
A drum cartridge 100 incorporating a 12T, a static eliminator 15T, a cleaning device 16T, a collected toner box 17T and the like is detachably provided on the upper main body 21.

It should be noted that on both sides of the drum cartridge 100, a mounting guide pin 157 is provided at a position corresponding to the center axis of the photosensitive drum 10T, and another mounting guide pin 158 is provided at a position slightly shorter than the drum radius. Is provided. Upper body 2
When 1 rotates about the support shaft 2 of the lower body 22 by about 45 °, the right hand guide also rotates about the other support shaft and opens.

In this way, the upper main body 21 is opened at approximately 45 °, and the drum cartridge 100 is ready for attachment / detachment.
When the 158 is inserted and mounted so as to slide along the guide grooves 18A and the mounting surface 18B provided on the upper main body frame 18 on both sides of the upper main body 21, the mounting guide pin 157 is stopped at the bottom of the guide groove. The other guide pins 158 described above are mounted on the mounting surface 18
Placed on B. A bulge portion 18C is provided at the end of the mounting surface 18B so that the guide pin 158 cannot easily get over if the guide pin 158 is accidentally moved against the dead weight of the drum cartridge 100.
In this state, the support portion is formed at the first position, and the drum cartridge 100 is safely placed in the first position.

A clamp mechanism 150 is provided on both sides of the rear portion of the drum cartridge 100. This is spindle 1
A clamp lever 151 rotatably supported by 52 is biased to rotate counterclockwise by a coil spring 153 provided between the frame of the drum cartridge 100 and the clamp lever 151.

A hook 151B is formed at the upper end portion of the clamp lever 151, and the lever 151 is rotated clockwise by a finger against the bias of the coil spring 153 at the lower end portion in the left side of the drawing. A knob 151A that can be used is provided.

On the other hand, support pins 155 at the second position are provided on both sides of the upper body frame 18.

The drum cartridge 10 in the first position
0 indicates that when the hook 151B is guided by the support pin 155 against the urging force of the spring 153, the hook 151B is rotated by about 45 ° upward with the pin 157 as a fulcrum, and the hook 151B is attached thereto. The support pin 155 is mounted in a clamped state by a force. In this way, the support portion at the second position is formed. At this time, the frame surface 160A of the upper main body 1B and the end surface 160B of the drum cartridge 100 form a recovery path for the recording paper P. This is the second mounted state shown in FIG.

Then, in order to return it to the state of the chain double-dashed line in FIG. 11 or the state of the first position shown in FIG. 10 by removing it, while slightly lifting the drum cartridge, put a finger on the knob 151A and pull it to the left. Doing so causes hook 151B to pin 155
Can be returned to the first position once.

Then, the drum cartridge 100 is removed from the upper main body 21 by moving the drum cartridge 100 so that the mounting guide pins 157 and 158 are separated from the guide groove 18A and the mounting surface 18B. Will be possible.

Next, the positional relationship when the transfer device 24T and the fixing device 23T are mounted on the lower main body 22 will be described with reference to FIG.

A guide pin 51T and a guide pin 53T are provided on the shelf 50T provided in the lower main body 22 for guiding the transfer and transport unit 30T and the fixing unit 23T vertically (in the direction of the white line arrow in the figure). Has been. The guide pin 51T and the guide pin 53T are the lower body at the same time.
It also serves as a positioning member that regulates the relative positional relationship with respect to 22, so that it can be positioned in the front side and the back side facing the drawing so that it can be positioned in the moving direction of the transfer paper and the direction orthogonal to the moving direction of the transfer paper. Two are arranged. Transfer device corresponding to the guide pins 51T and 53T
A guide hole 52T and a guide hole 54T, which are fitted to the guide pins as positioning members, are provided on the lower surfaces of the 24T and the fixing device 23T.
Are provided respectively. The transfer device 24T and the fixing device 23T, which are vertically guided from above and positioned relative to each other as described above, have a shelf portion by a tightening screw or the like (not shown).
It is fixed at 50T.

[0076]

As described above, in the image forming apparatus according to the first aspect of the present invention, the drum cartridge and the developing cartridge are attached / detached regardless of whether the developing cartridge is attached or not when the drum cartridge is attached / detached. At that time, both of them could be attached or detached without damaging the constituent members of each other regardless of whether the drum cartridge was attached or not. In addition, it is possible to use a developing cartridge having a simple structure in which the developing cartridge casing has no biasing means.

Further, in the image forming apparatus according to the fifth aspect of the present invention, the defective drive transmission due to the attachment and detachment of the developing cartridge is eliminated. In addition, since the drive can be released even with the drum cartridge installed, the drum cartridge and the developing cartridge can be installed or removed regardless of whether the developing cartridge is installed or not. It became detachable regardless of the type.

Further, in the image forming apparatus according to the invention of claim 9, the drum cartridge and the developing cartridge are attached to the drum cartridge regardless of whether the developing cartridge is attached or not when the drum cartridge is attached or detached. It is an object of the present invention to obtain an image forming apparatus which can be attached and detached without damaging the constituent members of each other regardless of whether the image forming apparatus is attached or not. Drive transmission failure due to attachment / detachment of developer cartridge has disappeared. In addition, since the drive can be released even with the drum cartridge attached, the drum cartridge and the developing cartridge can be attached to or detached from the drum cartridge regardless of whether the developing cartridge is attached or not.
When the developing cartridge was attached or detached, regardless of whether the drum cartridge was attached or not, the defective drive transmission was eliminated even when the drum cartridge was attached or detached. In addition, it is possible to use a developing cartridge having a simple structure in which the developing cartridge casing has no biasing means.

[Brief description of drawings]

FIG. 1 is an overall configuration diagram of an image forming apparatus.

FIG. 2 is an external perspective view of a developing cartridge.

FIG. 3 is a perspective view showing configurations of a developing device biasing mechanism and a drive gear bias releasing mechanism.

FIG. 4 is a top view of a developing device urging mechanism 60.

FIG. 5 is a perspective view showing a drive system of a developing device and an image forming apparatus.

FIG. 6 is a partial configuration diagram of a drive system.

FIG. 7 is a top view showing the operation of the drive gear bias release mechanism.

FIG. 8 is a partial configuration diagram of the image forming apparatus with an upper main body closed.

FIG. 9 is a partial configuration diagram of the image forming apparatus with an upper main body opened.

FIG. 10 is a schematic view of a state where the upper main body is opened.

FIG. 11 is another schematic view of the state where the upper main body is opened.

FIG. 12 is a configuration diagram of a conventional image forming apparatus.

FIG. 13 is a configuration diagram of still another conventional image forming apparatus.

[Explanation of symbols]

 C1 Color cartridge C2 Black cartridge C3Y, C3M, C3C, C3K Developer C4 Through window C8 Cartridge positioning hole C13 Casing G41A, G41 Gears S45Y, S45M, S45C, S45K Coil spring 50 Body frame 51 Body through window 60 Developer biasing mechanism 61Y, 61M, 61C, 61K Leaf spring 62 Leaf spring drive cam 70 Drive gear bias release mechanism 71 Gear pressing plate 72 Gear pressing plate driving plate 80 Connecting plate 85 Upper and lower body connecting plate

Claims (9)

[Claims] 1. A support means for supporting a developing device so as to be capable of contacting and separating from an image carrier, a positioning means for positioning the image forming apparatus main body, and a casing having an opening, and being detachable from the apparatus main body of the image forming apparatus. A developing cartridge, positioning engaging means for engaging the positioning means in a state where the developing cartridge is mounted in the image forming apparatus main body, the developing device in the first state of the image forming apparatus main body A developing device urging means for urging the opening portion so as to move the developing cartridge so as to move in a direction, and a guide means for guiding the developing cartridge in the attachment / detachment direction in the second state of the image forming apparatus main body. Image forming apparatus. 2. The image forming apparatus according to claim 1, wherein the developing device urging means has an urging releasing means for releasing the urging by the developing device urging means in the second state. 3. The first state is a state in which an image can be formed, and the second state is a state in which the developing cartridge can be attached to and detached from the main body of the image forming apparatus. The image forming apparatus according to 1 or 2. 4. The image forming apparatus according to claim 1, further comprising a split opening / closing means and a connecting means for operating the urging release means in cooperation with the split opening / closing means.
Or the image forming apparatus described in 3. 5. A developing cartridge having a developing device and detachable from the main body of the image forming apparatus; supporting means for supporting the developing device so that it can be brought into contact with and separated from the image carrier; and a drive shaft which rotates integrally. Drive means that is movably supported in the axial direction by means of which the driving force is transmitted to the developing device, and an urging force that moves the driving means in the axial direction to displace the driving force to the developing device. And drive urging means supported by the drive shaft, and drive releasing means for releasing the drive transmission of the developing device by moving the drive means in the axial direction against the urging force of the drive urging means. An image forming apparatus comprising: 6. The developing device releasing means for separating the developing device from the image carrier when the image forming apparatus main body is in a state where the developing cartridge is detachable from the main body. Image forming device. 7. A developing device positioning means for positioning the developing device at a predetermined position with respect to the image carrier when the main body of the image forming apparatus is in a state where the developing cartridge cannot be detached from the main body. The image forming apparatus according to claim 5. 8. The image forming apparatus according to claim 5, 6 or 7, further comprising: split opening / closing means of the image forming apparatus; and connecting means for operating the drive releasing means in cooperation with the split opening / closing means. apparatus. 9. A support means for supporting a developing device so as to be capable of contacting and separating from an image carrier, a positioning means for positioning the main body of the image forming apparatus, and a casing having an opening, which is detachable from the main body of the image forming apparatus. A developing cartridge, positioning engaging means for engaging the positioning means in a state where the developing cartridge is mounted in the image forming apparatus main body, the developing device in the first state of the image forming apparatus main body Developing unit urging means for urging through the opening so as to move in the direction, and guide means for guiding the developing cartridge in the attachment / detachment direction in the second state of the image forming apparatus main body are integrally rotated. A driving unit that is movably supported in the axial direction by a driving shaft and that transmits a driving force to the developing unit; and a position that moves the driving unit in the axial direction and that transmits the driving force to the developing unit. And a drive biasing unit that is supported by the drive shaft and that moves the drive unit in the axial direction against the biasing force of the drive biasing unit to transmit the drive transmission of the developing device. An image forming apparatus comprising drive releasing means for releasing.