JP2020184009A - Image forming apparatus - Google Patents

Abstract

To provide an image forming apparatus that can prevent a developing cartridge from dropping off from a mounting position without impairing operability during attachment/detachment of the developing cartridge.SOLUTION: A pressing spring 102 takes a first urging position in which a developing door 92 is at a closed position and a developing cartridge 70 is urged and the developing cartridge 70 is at an image formation position, a second urging position in which the developing door 92 is at an intermediate position and an urging force for urging the developing cartridge 70 becomes smaller than the self weight of the developing cartridge 70 and the developing cartridge 70 moves from the image formation position to a non-image formation position, and a third urging position in which the developing door 92 is at an open position and while a drum cartridge 60 moves to the non-image formation position, the developing cartridge 70 moves from the non-image formation position to a second non-image formation position through the image formation position.SELECTED DRAWING: Figure 4

Description

The present invention is an image forming apparatus such as a copying machine or a printer.

In the image forming apparatus, there is known an image forming apparatus in which a drum cartridge provided with a photosensitive drum and a developing cartridge provided with a developing roller are detachably supported. As such a developing cartridge, it is known that a positioning boss projecting outward in the axial direction of the developing roller is guided to a mounting position along a guide groove in the device main body to be mounted on the device main body. Has been done.

Such a developing cartridge is generally urged toward the downstream side in the attachment / detachment direction by an elastic member installed in a guide groove in the main body of the apparatus and supported at the mounting position. In the above configuration, if the developing cartridge receives a force exceeding the urging force of the elastic member in the attachment / detachment direction due to, for example, vibration during transportation, the developing cartridge may get over the elastic member and fall off from the mounting position. There is. Therefore, as in Patent Document 1, there is a device that prevents the mounting position from falling off due to an external force by providing the mounting position in a downward direction substantially perpendicular to the attachment / detachment direction.

Japanese Unexamined Patent Publication No. 2016-138994

However, in Patent Document 1, when the user takes out the developing cartridge from the inside of the apparatus main body, the developing pressing member that presses the second protrusion of the developing cartridge upward in conjunction with the opening operation of the first cover is released from the second protrusion. Leave. Therefore, the weight of the developing cartridge supports the second protrusion at the lowermost position of the third portion of the first developing guide. The user must move the second protrusion along a dogleg-shaped guide formed by the third portion and the second portion while grasping the developing grip portion of the developing cartridge and lifting the second protrusion. .. Therefore, the second protrusion is caught on the wall surface of the third portion, which greatly impairs the operability when the developing cartridge is taken out from the inside of the apparatus main body.

The present invention solves the above-mentioned problems, and an object of the present invention is to provide an image forming apparatus capable of suppressing dropping from a mounting position without impairing operability when attaching and detaching a developing cartridge. Is.

A typical configuration of an image forming apparatus according to the present invention for achieving the above object is an apparatus main body, a drum cartridge provided with an image carrier detachably attached to the apparatus main body, and attachment / detachment to the apparatus main body. In an image forming apparatus including a developing cartridge including a developer carrier that can be mounted, the apparatus main body includes a drum guide that guides the drum cartridge, a developing guide that guides the developing cartridge, and the above. A first opening / closing member that can have an open position that exposes the first opening for attaching / detaching the drum cartridge and a closed position that covers the first opening, an open position that exposes the second opening for attaching / detaching the developing cartridge, and the first. (2) The second opening / closing member capable of having a closed position covering the opening and an intermediate position between the open position and the closed position, and the developer carrier being urged toward the image carrier, said. The urging means for moving the developing cartridge to the image forming position and the urging releasing means for releasing the urging state of the urging means in conjunction with the opening / closing operation of the second opening / closing member. The means includes a first urging position in which the second opening / closing member is in the closed position, the developing cartridge is urged by the urging means, and the developing cartridge is in the image forming position, and the second opening / closing member. Is in the intermediate position, and the urging force for urging the developing cartridge by the urging means becomes smaller than the weight of the developing cartridge, so that the developing cartridge moves from the image forming position to the non-image forming position. With the second urging position and the second opening / closing member in the open position and the drum cartridge moved to the non-image forming position, the developing cartridge passes through the image forming position from the non-image forming position. It is characterized by taking a third urging position that moves to the second non-image forming position.

According to the present invention, it is possible to suppress the development cartridge from falling off from the mounting position without impairing the operability when attaching and detaching the developing cartridge.

It is sectional drawing which shows the structure of the image forming apparatus. FIG. 5 is a cross-sectional view showing a state in which a cartridge is attached / detached in an image forming apparatus with the document reading unit, the ejection tray, and the developing door open. It is sectional drawing which shows the structure of the mounting part of the development cartridge. It is sectional drawing which shows the structure of the mounting part of the development cartridge when the development door is a closed position in 1st Embodiment. It is sectional drawing which shows the structure of the mounting part of the development cartridge when the development door is in an intermediate position in 1st Embodiment. It is sectional drawing which shows the structure of the mounting part of the development cartridge when the development door is in an open position in 1st Embodiment. It is sectional drawing which shows the structure of the cartridge moving mechanism when the drum cartridge is attached and detached with the development door and the discharge tray open in 1st Embodiment. It is sectional drawing which shows the structure of the mounting part of the development cartridge when the development door is a closed position in 2nd Embodiment. It is sectional drawing which shows the structure of the mounting part of the development cartridge when the development door is in an intermediate position in 2nd Embodiment. It is sectional drawing which shows the structure of the mounting part of the development cartridge when the development door is in an open position in 2nd Embodiment.

An embodiment of the image forming apparatus according to the present invention will be specifically described with reference to the drawings.

[First Embodiment]
First, the configuration of the first embodiment of the image forming apparatus according to the present invention will be described with reference to FIGS. 1 to 7.

<Image forming device>
The configuration of the image forming apparatus will be described with reference to FIGS. 1 and 2. FIG. 1 is a cross-sectional view showing the configuration of an image forming apparatus. FIG. 2 is a cross-sectional view showing a state in which a cartridge is attached / detached in an image forming apparatus with the document reading unit, the ejection tray 90, and the developing door 92 open. The image forming apparatus 1 shown in FIG. 1 shows an example of a laser beam printer. In the following description, it is assumed that the front, front, and front ends of the image forming apparatus 1 indicate the right side of FIG. 1, and the rear, rear, and rear ends indicate the left side of FIG.

In FIG. 1, the device main body 2 of the image forming apparatus 1 has an image reading unit 4 for reading image information of a document and a sheet feeding device 10 for feeding a sheet S such as paper to the image forming unit 3. And are provided. Further, the apparatus main body 2 is provided with an image forming unit 3 that forms an image by an electrophotographic method, and a fixing unit 40 as a fixing means for fixing the image formed by the image forming unit 3 on the sheet S. There is.

The sheet feeding device 10 is arranged at the bottom of the device main body 2. The sheet feeding device 10 includes a separation roller 11, a feeding roller 12, a feeding tray 13, a middle plate 14, and a pressing spring 15 that presses the middle plate 14 upward. The feeding tray 13 accommodates the sheet S. Further, the developing door 92 is rotatably provided with respect to the apparatus main body 2 with the developing door shaft 92a as the center of rotation.

The developing door 92 is provided with a bypass tray 91. The manual feed tray 91 is configured to rotate about the manual feed tray support shaft 91a. The bypass tray 91 is stored so as to overlap the developing door 92 as shown by the solid line in FIG. 1, and the position where the sheet S can be placed on the bypass tray 91 as shown by the broken line in FIG. Rotate between.

<Image forming part>
The image forming unit 3 includes a photosensitive drum 61 as an image carrier for forming a toner image, and a transfer roller 31 as a transfer means for transferring the toner image formed on the photosensitive drum 61 to the sheet S. Further, the image forming unit 3 includes a cleaning roller 62 as a cleaning means, a corona charger 63 as a charging means for uniformly charging the surface of the photosensitive drum 61, a developing roller 71 as a developer carrier, and the like. ing.

<Drum cartridge>
The photosensitive drum 61 as an image carrier, the cleaning roller 62, and the corona charger 63 are supported by a drum frame 64 provided in the drum cartridge 60. The drum cartridge 60 includes a drum grip portion 65 that is rotatably supported around a drum grip shaft 65a arranged on the front side of the device main body 2 of the drum frame 64.

The drum cartridge 60 is detachably attached to the apparatus main body 2. As shown in FIG. 2, the drum cartridge 60 opens the discharge tray 90 rotatably provided about the discharge tray shaft 90a with respect to the device main body 2, and the user grips the drum grip portion 65 to grip the device main body. It can be attached and detached in the direction of arrow A in FIG. The discharge tray 90 as the first opening / closing member may have an open position for exposing the first opening 9 for attaching / detaching the drum cartridge 60 shown in FIG. 2 and a closed position for covering the first opening 9 shown in FIG.

<Development cartridge>
The developing roller 71 as a developing agent carrier is provided on the developing cartridge 70. The developing cartridge 70 includes a developing frame body 72 and a developing grip portion 73 provided on the front side of the apparatus main body 2. The developing frame body 72 is provided with a developing first protrusion 74 and a developing second protrusion 75 as at least two protrusions. One of the developing first protrusions 74 provided on the developing frame 72 is arranged substantially coaxially with the developing roller 71 as a developing agent carrier provided on the developing cartridge 70. The other development second projection 75 is arranged on the front side (right side in FIG. 2) of the apparatus main body 2 in the attachment / detachment direction of the development cartridge 70 with respect to the development first projection 74.

The developing cartridge 70 is detachably attached to the apparatus main body 2. As shown in FIG. 2, the user can open the developing door 92, grip the developing grip portion 73, and attach / detach the developing cartridge 70 to / from the apparatus main body 2 in the direction of arrow B in FIG. When the developing cartridge 70 is mounted on the apparatus main body 2, the developing first projection 74 is guided by the guide portion 111a as the first guide portion of the first development guide 111 shown in FIG. 3, and then passes through the guide portion 111b. It is guided by the guide unit 111c and the regulation unit 111d as the second guide unit. Further, the development second protrusion 75 is guided by the guide portion 112a as the first guide portion of the second development guide 112, and then guided to the guide portion 112c and the regulation portion 112d as the second guide portion via the guide portion 112b. Will be done.

<Fixing unit>
The fixing unit 40 includes a heating unit 41 and a pressurizing roller 42. The fixing unit 40 is configured as one unit, and is replaceably attached to the apparatus main body 2.

<Image formation operation>
Next, the image forming operation of the image forming apparatus 1 will be described. The surface of the photosensitive drum 61 rotating in the clockwise direction of FIG. 1 is cleaned in advance by the cleaning roller 62, and the surface of the photosensitive drum 61 is uniformly charged by the corona charger 63.

After that, the laser beam 80a is irradiated onto the surface of the photosensitive drum 61 from the laser scanner 80 as an exposure means provided in the apparatus main body 2 based on an image signal sent from a host computer (not shown). As a result, an electrostatic latent image is formed on the surface of the photosensitive drum 61. Next, an electrostatic latent image formed on the surface of the photosensitive drum 61 is developed by toner as a developer supported on the surface of the developing roller 71 provided on the developing cartridge 70, and is developed on the surface of the photosensitive drum 61. A toner image is formed on the surface.

On the other hand, the feeding roller 12 provided in the seat feeding device 10 starts rotating at a predetermined timing, and in conjunction with this, the middle plate is urged to the feeding roller 12 side by the urging force of the pressing spring 15. 14 rotates upward. As a result, the tip end portion of the sheet S loaded on the middle plate 14 is pressed against the feeding roller 12 with a predetermined force.

Here, the feeding roller 12 is controlled to rotate in the counterclockwise direction of FIG. 1 only during feeding, and feeds the pressure-welded sheet S by frictional force. When a plurality of sheets S on the middle plate 14 are sent out at the same time, only the uppermost sheet S is separated by the action of the separation roller 11 and transported to the downstream.

The uppermost sheet S separated by the separation roller 11 is conveyed by the transfer roller 6, and the tip end portion is abutted against the nip portion of the stopped resist roller 7 to correct the skew. After that, the resist roller 7 rotates at a predetermined timing and is conveyed to the transfer nip portion 30 formed by the photosensitive drum 61 and the transfer roller 31. In the transfer nip portion 30, the toner image formed on the surface of the photosensitive drum 61 is electrically attracted by the transfer roller 31 and transferred to the sheet S.

After that, in the transfer nip portion 30, the sheet S on which the toner image is transferred is sandwiched between the photosensitive drum 61 and the transfer roller 31 and conveyed to the fixing unit 40 provided with the heating unit 41 and the pressure roller 42. In the fixing unit 40, the toner image is fixed to the sheet S by heating and pressurizing the sheet S carrying the toner image. After that, the sheet S on which the toner image is fixed is discharged by the discharge roller 50 onto the discharge tray 90 provided on the upper surface of the apparatus main body 2.

<Main body casing>
FIG. 3 is a cross-sectional view showing the configuration of the mounting portion of the developing cartridge 70. FIG. 4 is a cross-sectional view showing the configuration of the mounting portion of the developing cartridge 70 when the developing door 92 is in the closed position. As shown in FIG. 4, the main body casing 5 includes a pair of side walls (not shown), a developing pressing mechanism 100, and a link unit 120.

A pair of side walls (not shown) are arranged on the left and right inside the main body casing 5. A pair of side walls (not shown) are symmetrical. Therefore, only the side wall on the left side of the main body will be described. As shown in FIGS. 3 and 4, the side walls (not shown) include a first development guide 111, a second development guide 112 arranged below the first development guide 111, a drum guide 113, and a development pressing mechanism 100. It has. The drum guide 113 guides the drum cartridge 60.

<First development guide>
The first development guide 111 guides the first development protrusion 74 of the development cartridge 70. The first developing guide 111 is arranged substantially in the vertical center of the side wall (not shown), and as shown in FIG. 3, the first developing guide 111 extends in an upward manner from the front to the rear of the apparatus main body 2, and then in front of the apparatus main body 2. It has a substantially V-shape that bends downward. Specifically, the first development guide 111 includes guide units 111a to 111c and regulation units 111d. The guide portion 111a is arranged at substantially the center in the vertical direction of the side wall (not shown), and extends upward from the front of the apparatus main body 2 toward the rear. The guide portion 111b extends from the upper end portion of the guide portion 111a on the rear side of the device main body 2 toward the lower side on the rear side of the device main body 2.

The guide portion 111c extends from the lower end of the guide portion 111b on the rear side of the device main body 2 toward the lower front side of the device main body 2 and connects to the upper end portion of the regulation portion 111d on the rear side of the device main body 2. The regulation unit 111d is provided at the lower end portion on the front side of the device main body 2 of the guide unit 111c. The guide portion 111c extends in parallel with the straight line 8 connecting the rotation center 61a of the photosensitive drum 61 and the rotation center 71a of the developing roller 71. The regulation unit 111d supports the development first projection 74 of the development cartridge 70 in a state of being mounted on the apparatus main body 2.

<Second development guide>
The second development guide 112 guides the development second protrusion 75 of the development cartridge 70. The second development guide 112 is arranged below the first development guide 111, and as shown in FIG. 3, extends upward from the front of the apparatus main body 2 toward the rear, and then extends downward on the front side of the apparatus main body 2. It has a substantially V-shape that bends toward. Specifically, the second development guide 112 includes guide units 112a to 112c and regulation units 112d. The guide portion 112a is arranged substantially in the center of the side wall in the vertical direction (not shown), and extends upward from the front of the device main body 2 toward the rear. The guide portion 112b extends from the upper end portion of the guide portion 112a on the rear side of the device main body 2 toward the lower side on the rear side of the device main body 2.

The guide portion 112c extends from the lower end portion on the rear side of the device main body 2 of the guide portion 112b toward the lower side on the front side of the device main body 2 and connects to the upper end portion on the rear side of the device main body 2 of the regulation portion 112d. The regulation unit 112d is provided at the lower end portion on the front side of the device main body 2 of the guide unit 112c. The guide portion 112c of the second development guide 112 extends in parallel with the guide portion 111c of the first development guide 111.

The first development guide 111 and the second development guide 112 have guide portions 111a and 112a as first guide portions extending in the direction of arrow B in FIG. 6, which is the attachment / detachment direction for attaching / detaching the development cartridge 70 from the second opening 16. Further, the first development guide 111 and the second development guide 112 have a second guide portion for guiding the movement between the image formation position shown in FIG. 4 and the non-image formation position shown in FIG. 5 of the development cartridge 70. .. The second guide unit is composed of a guide unit 111c and a regulation unit 111d, a guide unit 112c and a regulation unit 112d.

<Drum guide>
As shown in FIG. 3, the drum guide 113 is arranged above the first developing guide 111, and has a concave shape from the inside to the outside of the apparatus main body 2 on the side wall (not shown). As shown in FIG. 3, the drum guide 113 extends from the upper side of the rear side of the device main body 2 of the regulation portion 111d of the first development guide 111 toward the upper side of the front side of the device main body 2. The drum guide 113 is formed so that the width increases toward the upper side of the front side of the apparatus main body 2.

<Pressing mechanism of developing cartridge>
Next, the configuration of the pressing mechanism of the developing cartridge 70 will be described with reference to FIG. The development pressing mechanism 100 shown in FIG. 4 is arranged between a side wall (not shown) and the development cartridge 70 in the width direction of the apparatus main body 2, and moves the development cartridge 70 in conjunction with the opening / closing operation of the development door 92. Do. The developing pressing mechanism 100 is arranged below the second developing guide 112, and includes a developing pressing member 101, a pressing spring 102, a developing pressing cam 103, a cam drive gear 104, and a retracting spring 105. ..

One end of the retract spring 105 is locked to the cam receiving portion 101b, and the other end of the retract spring 105 is engaged with the rotating shaft 104b. As shown in FIG. 4, when the developing door 92 as the second opening / closing member is in the closed position, the developing cartridge 70 is urged by the pressing spring 102, and the developing cartridge 70 is in the image forming position, the pressing spring 102 is set. Take the first urging position.

The developing pressing member 101 shown in FIG. 4 is configured as an urging means for moving the developing cartridge 70 to the image forming position by urging the developing roller 71 as the developer carrier toward the photosensitive drum 61 as the image carrier. Will be done. The development pressing member 101 has a cam receiving portion 101b that is rotated around the development pressing shaft 101c by the development pressing cam 103. Further, the development pressing member 101 has a pressing portion 101a that rotates around the developing pressing shaft 101c and presses the developing second projection 75 provided on the developing cartridge 70. Further, the developing pressing member 101 is configured to have a pressing spring 102 having one end engaged with the cam receiving portion 101b and the other end engaging with the pressing portion 101a.

The development pressing member 101 has a pressing portion 101a that comes into contact with the developing second projection 75 of the developing cartridge 70, receives the spring pressure of the pressing spring 102, and urges the developing cartridge 70 upward of the apparatus main body 2. Further, the developing pressing member 101 has a cam receiving portion 101b that comes into contact with the developing pressing cam 103 and restricts the movement of the pressing portion 101a due to the reaction force of the pressing spring 102. Further, the developing pressing member 101 is configured to have a developing pressing shaft 101c which is supported by a side wall (not shown) and rotatably supports the pressing portion 101a and the cam receiving portion 101b. Further, the cam receiving portion 101b is urged to the front of the apparatus main body 2 by the retracting spring 105, and the cam receiving portion 101b and the developing pressing cam 103 are always in contact with each other.

The development pressing cam 103 is rotatably supported around a rotation shaft 103e with respect to a side wall (not shown). The development pressing cam 103 includes a cam gear portion 103b arranged coaxially with the rotation shaft 103e, a first cam portion 103a that comes into contact with the cam receiving portion 101b due to the rotational posture of the development pressing cam 103, and a second cam portion 103c. And a third cam portion 103d.

The first cam portion 103a and the third cam portion 103d are located at positions facing each other by 180 ° with respect to the rotation shaft 103e of the developing pressing cam 103, and a convex cam surface symmetrical with respect to the rotation shaft 103e is formed. It is formed. The second cam portion 103c is arranged at a position approximately 90 ° about the rotation shaft 103e of the development pressing cam 103 with respect to each of the first cam portion 103a and the third cam portion 103d.

Further, the cam gear portion 103b of the development pressing cam 103 meshes with the cam drive gear 104. The cam drive gear 104 rotates integrally with the rotating body 104a about the rotating shaft 104b. The rotating body 104a is connected to the developing door 92 via the developing link 106. Here, in the present embodiment, the number of teeth of the cam gear portion 103b and the number of teeth of the cam drive gear 104 are configured to have a one-to-two relationship. That is, when the cam drive gear 104 rotates by 90 °, the development pressing cam 103 rotates by 180 °.

One end of the developing link 106 provided on the front side of the apparatus main body 2 is rotatably supported by the developing first link portion 106a with respect to the developing door 92. Further, the developing link 106 is rotatably supported by the developing second link portion 106b with respect to the rotating body 104a provided with the cam drive gear 104 at the other end provided on the rear side of the apparatus main body 2. There is.

When the developing door 92 is opened and closed by rotating around the developing door shaft 92a, the developing link 106 moves in the front-rear direction of the apparatus main body 2 in conjunction with the opening and closing operation of the developing door 92. As a result, the rotating body 104a rotates about the rotating shaft 104b, and the cam drive gear 104 provided on the rotating body 104a rotates.

As a result, the development pressing cam 103 provided with the cam gear portion 103b that meshes with the cam drive gear 104 rotates about the rotation shaft 103e, and the cam receiving portion 101b moves along the cam surface of the development pressing cam 103. It rotates around 101c. As the cam receiving portion 101b rotates, the pressing portion 101a urged by the pressing spring 102 rotates around the developing pressing shaft 101c. As a result, the posture of the developing pressing member 101 is changed, and the position of the developing cartridge 70 is moved via the developing second projection 75 urged by the pressing portion 101a of the developing pressing member 101.

<Development door>
FIG. 5 is a cross-sectional view showing the configuration of the mounting portion of the developing cartridge 70 when the developing door 92 is in the intermediate position. FIG. 6 is a cross-sectional view showing the configuration of the mounting portion of the developing cartridge 70 when the developing door 92 is in the open position. The developing door 92 is rotatably supported by the developing door shaft 92a with respect to the apparatus main body 2.

As shown in FIG. 2, the developing door 92 as the second opening / closing member can take an open position that exposes the second opening 16 to which the developing cartridge 70 is attached / detached. Further, as shown in FIG. 4, the developing door 92 may take a closed position covering the second opening 16 in which the developing door 92 is completely closed. Further, the developing door 92 can take an intermediate position shown in FIG. 5 between an open position shown in FIG. 2 and a closed position shown in FIG.

The intermediate position shown in FIG. 5 is an intermediate position in which the developing door 92 is rotated by approximately 45 ° about the developing door shaft 92a. The open position shown in FIG. 2 is an open position in which the developing door 92 rotates approximately 90 ° around the developing door shaft 92a and the second opening 16 in front of the apparatus main body 2 (on the right side in FIG. 2) is completely exposed. is there.

Consider the distance L1 from the center of the developing door shaft 92a shown in FIG. 6 to the center of rotation of the developing first link portion 106a of the developing link 106. Further, the distance L2 from the center of the rotation shaft 104b of the cam drive gear 104 to the rotation center of the development second link portion 106b of the development link 106 is considered. The distance L1 and the distance L2 are set to be equal to each other. As a result, the rotation amount (rotation angle) of the developing door 92 and the rotation amount (rotation angle) of the cam drive gear 104 have a one-to-one relationship. That is, the position of the developing cartridge 70 can be controlled in three stages by the opening / closing postures of the developing doors 92 shown in FIGS. 4 to 6.

<Drum cartridge support mechanism>
Next, the support mechanism of the drum cartridge 60 will be described with reference to FIG. The apparatus main body 2 includes a link unit 120 that constitutes a moving mechanism of the drum cartridge 60 having the drum first link 121, the drum second link 122, and the drum link guide 123.

<Drum moving member>
The apparatus main body 2 moves the drum cartridge 60 between the image forming position shown in FIG. 4 and the non-image forming position shown in FIG. 6 in conjunction with the opening / closing operation of the developing door 92 as the second opening / closing member. It has a member. This drum moving member is composed of a link unit 120. The link unit 120 has a drum first link 121 provided with drum holding portions 121a at one end for holding both ends of the photosensitive drum 61 in the longitudinal direction. Further, the link unit 120 is configured to have a drum second link 122 provided with a developing door engaging portion 122a that engages with the developing door 92 at one end.

The drum cartridge 60 is supported coaxially with the rotation center of the photosensitive drum 61 by the drum holding portion 121a of the drum first link 121. The drum first link 121 is provided with a link engaging protrusion 121b at an end opposite to the drum holding portion 121a. The link engaging hole 122b of the drum second link 122 is rotatably engaged with the convex portion of the link engaging protrusion 121b. The developing door engaging portion 122a provided at the end of the drum second link 122 opposite to the link engaging hole 122b is rotatably supported with respect to the developing door 92. As a result, the drum cartridge 60 moves via the link unit 120 in conjunction with the opening / closing operation of the developing door 92.

As shown in FIG. 4, the link unit 120 as the drum moving member takes the first position where the developing door 92 as the second opening / closing member is in the closed position and the drum cartridge 60 is in the image forming position. Further, the link unit 120 takes a second position in which the developing door 92 is in the intermediate position shown in FIG. 5 or the open position shown in FIG. 6 and the drum cartridge 60 is in the non-image forming position.

A drum link guide 123 is provided in order to limit the operation loci of the drum first link 121 and the drum second link 122. The drum link guide 123 is composed of two upper and lower bosses protruding inward of the main body from a side wall (not shown). The drum link guide 123 is arranged so as to sandwich the arm portion 121c of the drum first link 121 from the vertical direction of the apparatus main body 2.

As shown in FIG. 4, when the developing door 92 is in the closed position, the drum cartridge 60 is supported at the image forming position which is the most downstream of the drum guide 113. On the other hand, as shown in FIG. 5, as the developing door 92 opens, the drum cartridge 60 moves upward on the front side of the apparatus main body 2 via the drum first link 121 and the drum second link 122. I will go.

Then, when the developing door 92 comes to the intermediate position shown in FIG. 5, the drum cartridge 60 moves to a position where it does not interfere with the attachment / detachment trajectory of the developing cartridge 70. As a result, when the developing cartridge 70 is taken out from the apparatus main body 2, the photosensitive drum 61 and the developing roller 71 do not come into contact with each other and are damaged by rubbing or the like, causing image defects.

<Removal of developing cartridge>
Next, the operation of taking out the developing cartridge 70 mounted on the apparatus main body 2 will be described with reference to FIGS. 4 to 6. First, in order to access the developing cartridge 70, the user rotates the developing door 92 from the closed position shown in FIG. 4 in the clockwise direction of FIG. 5 about the developing door shaft 92a, and tilts the developing door 92 by approximately 45 °. Move to the intermediate position shown in 5.

By rotating the developing door 92 in the clockwise direction of FIG. 5, the developing link 106 moves to the front side (right side of FIG. 5) of the apparatus main body 2. As a result, the rotating body 104a rotates about the rotation shaft 104b in the clockwise direction of FIG. The cam drive gear 104 also rotates integrally with the rotating body 104a in the clockwise direction of FIG. 5 around the rotating shaft 104b. The cam gear portion 103b that meshes with the cam drive gear 104 rotates around the rotation shaft 103e in the counterclockwise direction of FIG. As a result, the development pressing cam 103 also rotates integrally with the cam gear portion 103b in the counterclockwise direction of FIG. 5 around the rotation shaft 103e.

Along with this, the developing pressing member 101 urged in the forward direction of the apparatus main body 2 by the retracting spring 105 rotates around the developing pressing shaft 101c in the counterclockwise direction of FIG. 5, and the cam receiving portion 101b The development pressing cam 103 moves to a position where it abuts on the second cam portion 103c of the minor axis portion.

Then, the weight of the developing cartridge 70 overcomes the extension force of the pressing spring 102, and the developing second projection 75 of the developing cartridge 70 moves from the guide portion 112c to the regulating portion 112d. At this time, the development first projection 74 of the development cartridge 70 also moves from the guide portion 111c to the regulation portion 111d. As a result, as shown in FIG. 4, the developing cartridge 70 moves from the image forming position where the developing roller 71 is in contact with or substantially in contact with the photosensitive drum 61 to the non-image forming position where the developing roller 71 is separated from the photosensitive drum 61. Moving. As shown in FIG. 5, the non-image forming position of the developing cartridge 70 is substantially below the image forming position.

At this time, the force with which the pressing portion 101a of the developing pressing member 101 pushes the developing second projection 75 upward by the urging force of the pressing spring 102 is assumed to be sufficiently smaller than the own weight of the developing cartridge 70. As shown in FIG. 5, the pressing spring 102 takes a second urging position. The second urging position considers the case where the developing door 92 as the second opening / closing member is in the intermediate position. At this time, the urging force on which the developing cartridge 70 is urged by the pressing spring 102 becomes smaller than the own weight of the developing cartridge 70, so that the developing cartridge 70 moves from the image forming position to the non-image forming position. ..

<Biasing release mechanism>
An urging release means for releasing the urging state of the pressing spring 102 is provided in conjunction with the opening / closing operation of the developing door 92 as the second opening / closing member. The urging release means is composed of a developing link 106, a rotating body 104a, a cam drive gear 104, a cam gear portion 103b, a developing pressing cam 103, and a developing pressing member 101. The development pressing cam 103 rotates in conjunction with the opening / closing operation of the developing door 92 as the second opening / closing member.

Next, the developing door 92 is further rotated in the clockwise direction of FIG. 6 about the developing door shaft 92a from the intermediate position shown in FIG. 5 to move to an open position tilted by approximately 90 ° shown in FIG. .. When the developing door 92 takes the open position shown in FIG. 6, the developing pressing cam 103 rotates approximately 180 ° from the posture position shown in FIG. 4 via the developing link 106, the rotating body 104a, the cam drive gear 104, and the cam gear portion 103b. To do. Then, in the development pressing cam 103, the third cam portion 103d on the major axis side comes into contact with the cam receiving portion 101b of the development pressing member 101.

The third cam portion 103d has a symmetrical shape with respect to the rotation center of the rotation shaft 103e and the first cam portion 103a on the major axis side. Therefore, the cam receiving portion 101b is supported at the same position as when the developing door 92 shown in FIG. 4 is in the closed position. As shown in FIG. 4, when the developing door 92 is in the closed position, the drum cartridge 60 is supported at the image forming position, and the developing cartridge 70 forms an image in which the developing roller 71 and the photosensitive drum 61 are in contact with each other or substantially in contact with each other. Supported in position.

Here, consider the case where the pressing spring 102 is in the first urging position shown in FIG. 4 and the drum cartridge 60 is not in the image forming position. At this time, as shown in FIG. 4, the developing cartridge 70 can pass through the space occupied by the photosensitive drum 61 as the image carrier when the drum cartridge 60 is in the image forming position. As a result, the position of the developing cartridge 70 when the pressing spring 102 is in the first urging position shown in FIG. 4 and the position of the developing cartridge 70 when the pressing spring 102 is in the third urging position shown in FIG. Approximately equal.

On the other hand, as shown in FIG. 6, when the developing door 92 is in the open position, the drum cartridge 60 is moved to the non-image forming apparatus by the link unit 120 interlocked with the opening / closing operation of the developing door 92. Therefore, the photosensitive drum 61 of the drum cartridge 60 and the developing roller 71 of the developing cartridge 70 do not come into contact with each other. At this time, the developing second protrusion 75 of the developing cartridge 70 is pushed upward by the urging force of the pressing spring 102 from the regulating portion 112d shown in FIG. 5 through the guide portion 112c to the guide portion 112b.

At this time, the development first projection 74 of the development cartridge 70 is also pushed upward from the regulation portion 111d shown in FIG. 5 through the guide portion 111c to the guide portion 111b. At this time, the pressing spring 102 shown in FIG. 6 takes the third urging position. The third urging position is that the development door 92 as the second opening / closing member is in the open position, and the development cartridge 70 moves the image forming position from the non-image forming device while the drum cartridge 60 is moved to the non-image forming position. It is an urging position that moves to the second non-image forming position via the route.

The developing cartridge 70 is attached to and detached from the apparatus main body 2. At that time, as shown in FIG. 6, the space occupied by the photosensitive drum 61 as the image carrier when the drum cartridge 60 is in the image forming position after the drum cartridge 60 is retracted to the non-image forming position is taken into consideration. The developing roller 71 as a developing agent carrier of the developing cartridge 70 moves through this space occupied by the photosensitive drum 61.

At this time, the development first protrusion 74 and the development second protrusion 75 of the development cartridge 70 move the guide portions 111b and 112b, respectively. The guide portions 111b and 112b are the guide portions 111a and 112a as the first guide portion of the first development guide 111 and the second development guide 112, the guide portion 111c and the regulation portion 111d as the second guide portion, and the guide portion 112c. And is provided between the regulatory unit 112d.

After that, the user grips the developing grip portion 73 of the developing cartridge 70 and takes it out from the apparatus main body 2 in the right direction of FIG. When the developing door 92 is in the open position shown in FIG. 6, the developing first projection 74 and the developing second projection 75 of the developing cartridge 70 are guided to the guide portion 111b and the guide portion 112b, respectively. Then, the developing grip portion 73 of the developing cartridge 70 is gripped and pulled out to the outside of the apparatus main body 2. At that time, the developing first projection 74 and the developing second projection 75 of the developing cartridge 70 are guided from the respective guide portions 111b and 112b to the respective guide portions 111a and 112a. By pulling out the developing cartridge 70 from there to the outside of the apparatus main body 2, the developing cartridge 70 is detached from the outside of the apparatus main body 2.

At this time, if the drum cartridge 60 is in the image forming position, it interferes with the take-out trajectory of the developing cartridge 70. In the present embodiment, the drum cartridge 60 retracts from the attachment / detachment locus of the development cartridge 70 in conjunction with the operation of opening the development door 92, so that the development cartridge 70 can be taken out from the apparatus main body 2.

<Installation operation of developing cartridge>
Next, the operation of mounting the developing cartridge 70 will be described. When the developing cartridge 70 is mounted on the main body 2, the developing door 92 and the developing cartridge 70 are operated in the reverse procedure of the above-mentioned taking-out operation of the developing cartridge 70. First, the user opens the developing door 92 to the open position, as shown in FIG. In that state, the development grip portion 73 of the development cartridge 70 is gripped, and the development first projection 74 and the development second projection 75 of the development cartridge 70 guide the guide portion 111a and the second development guide 112 of the first development guide 111. It is inserted at a position guided by each portion 112a.

In that state, the developing cartridge 70 is inserted to the left in FIG. At this time, the developing cartridge 70 reaches the guide portion 111b of the first development guide 111 and the guide portion 112b of the second development guide 112, respectively, when the first development protrusion 74 and the second development protrusion 75 of the development cartridge 70 reach the guide portion 112b of the first development guide 111. Be supported.

Next, the developing door 92 is rotated around the developing door shaft 92a in the counterclockwise direction of FIG. 6 to close the developing door 92, and the developing door 92 is moved to the intermediate position shown in FIG. At this time, the developing link 106 moves to the left in FIG. 5 in conjunction with the operation of closing the developing door 92, and the rotating body 104a rotates in the counterclockwise direction in FIG. 5 around the rotating shaft 104b. The cam drive gear 104 also rotates integrally with the rotating body 104a in the counterclockwise direction of FIG.

The cam gear portion 103b that meshes with the cam drive gear 104 rotates in the clockwise direction of FIG. 5, and the developing pressing cam 103 provided with the cam gear portion 103b rotates in the clockwise direction of FIG. 5 about the rotation shaft 103e. .. The cam receiving portion 101b is pulled in the forward direction (right side in FIG. 5) of the apparatus main body 2 by the retracting spring 105, and the developing pressing member 101 at the posture position in FIG. 6 is counterclockwise in FIG. Rotate clockwise. Then, the short diameter portion of the development pressing cam 103 comes into contact with the cam receiving portion 101b. As a result, the urging force of the pressing spring 102 against the developing second projection 75 of the developing cartridge 70 is reduced.

Then, the weight of the developing cartridge 70 overcomes the urging force of the pressing spring 102, and the developing second projection 75 of the developing cartridge 70 moves from the guide portion 112b of the second developing guide 112 to the regulating portion 112d via the guide portion 112c. At this time, the development first projection 74 of the development cartridge 70 also moves from the guide portion 111b of the first development guide 111 to the regulation portion 111d via the guide portion 111c. At this time, the developing cartridge 70 moves to the non-image forming position.

After that, the developing door 92 is further rotated around the developing door shaft 92a in the counterclockwise direction of FIG. 5, and the developing door 92 is moved to the closed position shown in FIG. Then, the development pressing cam 103 rotates in the clockwise direction of FIG. 4 about the rotation shaft 103e via the development link 106, the rotating body 104a, the cam drive gear 104, and the cam gear portion 103b. As a result, the development pressing member 101 is pushed upward by the first cam portion 103a on the major axis side of the development pressing cam 103. Then, the developing second projection 75 of the developing cartridge 70 is also pressed by the pressing portion 101a by the urging force of the pressing spring 102 and moves upward in the apparatus main body 2.

At this time, the development second protrusion 75 of the development cartridge 70 moves from the regulation portion 112d of the second development guide 112 to the guide portion 112c. Similarly, the development first projection 74 of the development cartridge 70 moves from the regulation portion 111d of the first development guide 111 to the guide portion 111c. As a result, the developing cartridge 70 moves to the image forming position.

At this time, the drum cartridge 60 moves from the non-image forming apparatus shown in FIG. 6 to the image forming position shown in FIG. 4 via the link unit 120 in conjunction with the operation of closing the developing door 92. As a result, the developing cartridge 70 is supported at a position where the developing roller 71 contacts or substantially contacts the photosensitive drum 61 of the drum cartridge 60. In this embodiment, the case where the drum cartridge 60 and the developing cartridge 70 are in the image forming position is considered. At this time, the photosensitive drum 61 as an image carrier provided on the drum cartridge 60 and the developing roller 71 as a developer carrier provided on the developing cartridge 70 are in contact with each other.

<Drum cartridge removal operation>
Next, the operation of taking out the drum cartridge 60 mounted on the apparatus main body 2 will be described with reference to FIG. 7. FIG. 7 is a cross-sectional view showing a configuration of a cartridge moving mechanism when the drum cartridge 60 is attached / detached with the developing door 92 and the discharge tray 90 open. First, the operation of detaching the drum cartridge 60 will be described with reference to FIG. 7. The drum cartridge 60 is taken out with the developing door 92 opened to the open position shown in FIG.

The drum cartridge 60 is held coaxially with the photosensitive drum 61 by the drum holding portion 121a so as to be gripped from the width direction of the photosensitive drum 61. When the developing door 92 moves to the open position shown in FIG. 7, the photosensitive drum 61 is unlocked by the drum holding portion 121a of the drum first link 121, and the drum cartridge 60 can be taken out of the apparatus main body 2. It becomes.

As shown in FIG. 7, the image reading unit 4 and the discharge tray 90 are moved upward from the closed position shown in FIG. 1 to the open position. The image reading unit 4 rotates in the counterclockwise direction of FIG. 7 about the rotation shaft 4a. The discharge tray 90 rotates in the counterclockwise direction of FIG. 7 about the discharge tray shaft 90a. From this state, the user can grip the drum grip portion 65 and take out the drum cartridge 60 from the apparatus main body 2 along the drum attachment / detachment locus shown in the direction of arrow A in FIG.

<Drum cartridge mounting operation>
The drum cartridge 60 is attached in the reverse procedure of taking out the drum cartridge 60 described above. First, the user moves the image reading unit 4 and the discharge tray 90 upward from the closed position shown in FIG. 1 to the open position shown in FIG. 7. After that, the drum cartridge 60 is inserted into the apparatus main body 2 along the drum guide 113 while gripping the drum grip portion 65. Then, the drum cartridge 60 is held by the drum holding portion 121a when it hits the drum holding portion 121a of the drum first link 121.

At this time, the drum cartridge 60 is inserted to a position where it does not interfere with the rotation locus of the discharge tray 90. Therefore, the discharge tray 90 can be closed by rotating it in the clockwise direction of FIG. 7 about the discharge tray shaft 90a. In this state, the image reading unit 4 is also similarly rotated around the rotation shaft 4a in the clockwise direction of FIG. 7 to move from the open position shown in FIG. 7 to the closed position shown in FIG.

Next, the developing door 92 is rotated from the open position shown in FIG. 6 to the intermediate position shown in FIG. Then, the drum cartridge 60 is directed from the non-image forming apparatus shown in FIG. 5 to the image forming position shown in FIG. 4 via the link unit 120 interlocking with the developing door 92 toward the lower left direction of FIG. 4 of the apparatus main body 2. I will move.

After that, as shown in FIG. 4, when the developing door 92 is in the closed position, the drum cartridge 60 moves to the image forming position which is the most downstream of the attachment / detachment locus shown in the direction of arrow A in FIG. After that, the development second projection 75 of the development cartridge 70 is pushed up in FIG. 4 in conjunction with the development door 92. At this time, in conjunction with the developing door 92, the pressing portion 101a is centered on the developing pressing shaft 101c via the developing link 106, the rotating body 104a, the cam drive gear 104, the cam gear portion 103b, the developing pressing cam 103, and the developing pressing member 101. It rotates in the clockwise direction of FIG. As a result, the developing second projection 75 of the developing cartridge 70 is pushed up by the pressing portion 101a in the upper part of FIG.

As a result, the developing cartridge 70 moves from the downward non-image forming apparatus shown in FIG. 2 to the upward image forming position shown in FIG. 3, and the photosensitive drum 61 of the drum cartridge 60 and the developing roller 71 of the developing cartridge 70 move. Contact or almost contact. By moving the developing cartridge 70 to the image forming position shown in FIG. 3, the drum cartridge 60 and the developing cartridge 70 can be supported at a position where image formation is possible. As a result, it is possible to suppress the development cartridge 70 from falling off from the mounting position without impairing the operability at the time of attachment / detachment.

[Second Embodiment]
Next, the configuration of the second embodiment of the image forming apparatus according to the present invention will be described with reference to FIGS. 8 to 10. It should be noted that the same components as those in the first embodiment are designated by the same reference numerals or the same member names even if the reference numerals are different, and the description thereof will be omitted. The difference between this embodiment and the first embodiment is that the positional relationship between the developing pressing member 101 and the developing cartridge 70 with respect to the opening / closing operation of the developing door 92 is different.

<Support structure of developing cartridge>
The support structure of the developing cartridge 70 will be described with reference to FIGS. 8 to 10. FIG. 8 is a cross-sectional view showing the configuration of the mounting portion of the developing cartridge 70 when the developing door 92 is in the closed position. FIG. 9 is a cross-sectional view showing the configuration of the mounting portion of the developing cartridge 70 when the developing door 92 is in the intermediate position. FIG. 10 is a cross-sectional view showing the configuration of the mounting portion of the developing cartridge 70 when the developing door 92 is in the open position.

As shown in FIG. 8, the apparatus main body 2 has a developing pressing member 101. The development pressing member 101 is configured as an urging means for urging the developing roller 71 as a developer carrier toward the photosensitive drum 61 as an image carrier to move the developing cartridge 70 to an image forming position. The development pressing member 101 has a spring receiving portion 101e that rotates about the development pressing shaft 101c in conjunction with the opening / closing operation of the development door 92 as the second opening / closing member. Further, the development pressing member 101 has a pressing portion 101a that rotates around the developing pressing shaft 101c and presses the developing second projection 75 provided on the developing cartridge 70.

Further, the developing pressing member 101 is configured to have a pressing spring 102 having one end engaged with the spring receiving portion 101e and the other end engaging with the pressing portion 101a. The spring receiving portion 101e receives the reaction force of the pressing spring 102. The developing pressing shaft 101c is supported by a side wall (not shown), and rotatably supports the pressing portion 101a and the spring receiving portion 101e, respectively.

Further, the development pressing member 101 includes a link engagement protrusion 101d that engages with the development link 106. As shown in FIG. 8, in the pressing spring 102, the developing door 92 as the second opening / closing member is in the closed position, the developing cartridge 70 is urged by the pressing spring 102, and the developing cartridge 70 is in the image forming position. Take the urging position.

The developing link 106 that links the developing door 92 and the developing pressing member 101 is engaged with the round boss of the link engaging protrusion 101d by the developing second link portion 106b having an elongated hole. As shown in FIG. 8, the elongated hole of the developing second link portion 106b has the elongated hole in the direction of arrow B in FIG. 10 when the developing door 92 is in the closed position and the developing cartridge 70 is in the image forming position. It is substantially parallel to the attachment / detachment direction of the development cartridge 70 shown. Then, the link engaging projection 101d is located on the front side (right side in FIG. 8) of the long hole device main body 2, and is supported at a position where a space is generated on the rear side (left side in FIG. 8) of the long hole device main body 2. To.

<Removal of developing cartridge>
When the developing cartridge 70 is in the image forming position shown in FIG. 8, the developing second projection 75 of the developing cartridge 70 is urged upward by the pressing portion 101a. At this time, the developing roller 71 of the developing cartridge 70 is supported at a position where it contacts or substantially contacts the photosensitive drum 61 of the drum cartridge 60. At this time, the development second protrusion 75 is located at the guide portion 112c of the second development guide 112.

The developing door 92 is moved from the closed position shown in FIG. 8 to the intermediate position shown in FIG. Then, as shown in FIG. 9, the developing link 106 moves to the front side (right side of FIG. 9) of the apparatus main body 2, and the link engaging projection 101d moves to the left side of the elongated hole of the developing second link portion 106b in FIG. Moving.

At this time, the drum cartridge 60 moves to the non-image forming apparatus shown in FIG. 9 along the drum guide 113 via the link unit 120 interlocked with the opening / closing operation of the developing door 92 as in the first embodiment. At this time, the development pressing member 101 and the development cartridge 70 do not move from the image forming position shown in FIG. As shown in FIG. 9, in the pressing spring 102, the developing door 92 as the second opening / closing member is in the intermediate position, the developing cartridge 70 is urged by the pressing spring 102, and the developing cartridge 70 is in the image forming position. Take the urging position.

Next, as shown in FIG. 10, when the developing door 92 is moved to the open position, the developing link 106 moves to the right in FIG. 10 in conjunction with the operation of opening the developing door 92. As a result, the link engaging projection 101d is pressed by the wall surface on the left side of FIG. 10 of the elongated hole of the developing second link portion 106b, and the developing pressing member 101 rotates in the clockwise direction of FIG. 10 around the developing pressing shaft 101c. To do. Then, the pressing force of the developing pressing member 101 on the developing second projection 75 becomes stronger. At this time, since the drum cartridge 60 has moved to the non-image forming apparatus shown in FIG. 10, it does not interfere with the developing cartridge 70.

As a result, the developing cartridge 70 can be moved upward of the apparatus main body 2. At this time, the development second protrusion 75 of the development cartridge 70 moves from the guide portion 112c of the second development guide 112 to the guide portion 112b. As a result, the user can take out the developing cartridge 70 from the apparatus main body 2. As shown in FIG. 10, in the pressing spring 102, the developing door 92 as the second opening / closing member is in the open position, and the developing cartridge 70 is moved to the non-image forming position while the drum cartridge 60 is moved to the non-image forming position. Take a third urging position to move.

<Installation operation of developing cartridge>
When the user mounts the developing cartridge 70, first, as shown in FIG. 10, the developing grip portion 73 of the developing cartridge 70 is gripped with the developing door 92 in the open position. Then, the development first protrusion 74 and the development second protrusion 75 of the development cartridge 70 are inserted at positions guided by the guide portion 111a of the first development guide 111 and the guide portion 112a of the second development guide 112, respectively. In that state, the developing cartridge 70 is inserted along the direction of arrow B in FIG. 10 toward the left side in FIG. Then, as shown in FIG. 10, the developing cartridge 70 is stopped at a position where the developing second projection 75 of the developing cartridge 70 comes into contact with the pressing portion 101a of the developing pressing member 101.

Next, the developing door 92 is moved from the open position shown in FIG. 10 to the intermediate position shown in FIG. At this time, the position of the link engaging projection 101d located on the left side of the elongated hole of the development second link portion 106b of the development link 106 is hardly changed in conjunction with the operation of closing the development door 92. Therefore, the developing cartridge 70 does not move from the non-image forming apparatus.

On the other hand, the drum cartridge 60 moves toward the rear side (left side in FIG. 9) of the apparatus main body 2 in conjunction with the operation of closing the developing door 92. At this time, at the intermediate position of the developing door 92 shown in FIG. 9, the developing cartridge 70 and the drum cartridge 60 are supported at positions where they do not interfere with each other.

After that, the developing door 92 moves from the intermediate position shown in FIG. 9 to the closed position shown in FIG. Then, the developing pressing member 101 rotates in the counterclockwise direction of FIG. 8 around the developing pressing shaft 101c in conjunction with the operation of closing the developing door 92. At this time, the link engaging projection 101d is pressed by the wall surface on the right side of FIG. 8 of the elongated hole of the developing second link portion 106b of the developing link 106 that moves to the left in FIG. As a result, the developing pressing member 101 rotates around the developing pressing shaft 101c in the counterclockwise direction of FIG. As a result, the development cartridge 70 moves to the image forming position due to the weight of the development cartridge 70.

At this time, the development second protrusion 75 of the development cartridge 70 is located at the guide portion 112c of the second development guide 112, and the development first protrusion 74 of the development cartridge 70 is located at the guide portion 111c of the first development guide 111. .. Further, the drum cartridge 60 also moves to the image forming position via the link unit 120 linked to the operation of closing the developing door 92.

In the present embodiment, the development cartridge 70 and the drum cartridge 60 can be attached and detached without moving the development cartridge 70 to the non-image forming apparatus shown in FIG. 5, as in the first embodiment. Further, the number of parts of the developing pressing member 101 is also smaller than that of the first embodiment, and the configuration can be simplified. The other configurations are the same as those in the first embodiment, and the same effects can be obtained.

<Other embodiments>
In each of the above-described embodiments, the laser scanner 80 is used as an example of the exposure unit, but an LED (Light Emitting Diode) unit can be applied as the exposure unit instead. Further, in each of the above-described embodiments, the development method in which the photosensitive drum 61 and the developing roller 71 are brought into contact with each other has been described, but the non-contact developing method in which a gap is provided between the photosensitive drum 61 and the developing roller 71 is provided. It can also be applied to.

In this case, consider the case where the drum cartridge 60 and the developing cartridge 70 are in the image forming position. At this time, the photosensitive drum 61 as an image carrier provided on the drum cartridge 60 and the developing roller 71 as a developer carrier provided on the developing cartridge 70 are in a non-contact state. Further, in each of the above-described embodiments, an example of the image forming apparatus 1 provided with the image reading unit 4 has been described, but the present invention can also be applied to an image forming apparatus not provided with the image reading unit 4.

61 ... Photosensitive drum (image carrier)
70 ... Development cartridge 71 ... Development roller (developer carrier)
92 ... Development door (second opening / closing member)
102 ... Pressing spring (urging means)

Claims (11)

With the device body
A drum cartridge having an image carrier that is detachably attached to the device body,
A developing cartridge provided with a developer carrier that is detachably attached to the device body, and
In an image forming apparatus equipped with
The device body
A drum guide that guides the drum cartridge and
A development guide that guides the development cartridge and
A first opening / closing member capable of having an open position for exposing the first opening for attaching / detaching the drum cartridge and a closed position for covering the first opening.
A second opening / closing member capable of having an open position for exposing the second opening to which the developing cartridge is attached / detached, a closed position for covering the second opening, and an intermediate position between the open position and the closed position.
An urging means that urges the developer carrier toward the image carrier to move the developing cartridge to an image forming position.
An urging release means for releasing the urging state of the urging means in conjunction with the opening / closing operation of the second opening / closing member.
Have,
The urging means
The first urging position where the second opening / closing member is in the closed position and the developing cartridge is urged by the urging means and the developing cartridge is in the image forming position.
The second opening / closing member is located at the intermediate position, and the urging force for urging the developing cartridge by the urging means is smaller than the weight of the developing cartridge, so that the developing cartridge is non-imaged from the image forming position. The second urging position that moves to the formation position and
With the second opening / closing member in the open position and the drum cartridge moved to the non-image forming position, the developing cartridge moves from the non-image forming position to the second non-image forming position via the image forming position. The third urging position to move to and
An image forming apparatus characterized by taking. The urging release means has a cam that rotates in conjunction with the opening / closing operation of the second opening / closing member.
The urging means
A cam receiving portion that rotates about a shaft by the cam,
A pressing portion that rotates about the axis and presses the developing cartridge,
A pressing spring in which one end is engaged with the cam receiving portion and the other end is engaged with the pressing portion.
The image forming apparatus according to claim 1, wherein the image forming apparatus has. With the device body
A drum cartridge having an image carrier that is detachably attached to the device body,
A developing cartridge provided with a developer carrier that is detachably attached to the device body, and
In an image forming apparatus equipped with
The device body
A drum guide that guides the drum cartridge and
A development guide that guides the development cartridge and
A first opening / closing member capable of having an open position for exposing the first opening for attaching / detaching the drum cartridge and a closed position for covering the first opening.
A second opening / closing member capable of having an open position for exposing the second opening to which the developing cartridge is attached / detached, a closed position for covering the second opening, and an intermediate position between the open position and the closed position.
An urging means that urges the developer carrier toward the image carrier to move the developing cartridge to an image forming position.
Have,
The urging means
The first urging position where the second opening / closing member is in the closed position and the developing cartridge is urged by the urging means and the developing cartridge is in the image forming position.
A second urging position in which the second opening / closing member is in the intermediate position, the developing cartridge is urged by the urging means, and the developing cartridge is in the image forming position.
A third urging position in which the developing cartridge moves from the image forming position to the non-image forming position while the second opening / closing member is in the open position and the drum cartridge moves to the non-image forming position.
An image forming apparatus characterized by taking. The urging means
A spring receiving portion that rotates around an axis in conjunction with the opening / closing operation of the second opening / closing member,
A pressing portion that rotates about the axis and presses the developing cartridge,
A pressing spring whose one end is engaged with the spring receiving portion and the other end is engaged with the pressing portion.
The image forming apparatus according to claim 3, wherein the image forming apparatus has. The device body
It has a drum moving member that moves the drum cartridge between the image forming position and the non-image forming position in conjunction with the opening / closing operation of the second opening / closing member.
The drum moving member is
The first position where the second opening / closing member is in the closed position and the drum cartridge is in the image forming position,
A second position where the second opening / closing member is in the intermediate position or the open position and the drum cartridge is in the non-image forming position.
The image forming apparatus according to any one of claims 1 to 4, wherein the image forming apparatus is characterized in that. The non-image forming position of the developing cartridge is substantially below the image forming position.
The development guide guides the movement between the first guide portion extending in the attachment / detachment direction for attaching / detaching the development cartridge from the second opening and the image forming position and the non-image forming position of the development cartridge. The image forming apparatus according to any one of claims 1 to 5, further comprising a guide portion. When the urging means is in the first urging position and the drum cartridge is not in the image forming position,
The position of the developing cartridge when the developing cartridge passes through the space occupied by the image carrier when the drum cartridge is in the image forming position, and the urging means is in the first urging position.
The position of the developing cartridge when the urging means is in the third urging position, and
The image forming apparatus according to claim 1 or 2, wherein the image forming apparatus is substantially equal to each other. When the developing cartridge is attached to and detached from the main body of the apparatus, the developer carrier of the developing cartridge is used when the drum cartridge is in the image forming position after the drum cartridge is retracted to the non-image forming position. The image formation according to claim 6, wherein the developing cartridge moves between the first guide portion and the second guide portion of the development guide through the space occupied by the image carrier. apparatus. The developing cartridge includes a developing frame body provided with at least two protrusions.
One first protrusion provided on the developing frame is arranged substantially coaxially with the developing agent carrier.
The other second protrusion is arranged in front of the first protrusion in the attachment / detachment direction of the development cartridge.
When the development cartridge is mounted on the apparatus main body, the first protrusion is guided to the first guide portion of the development guide and then guided to the second guide portion, and the second protrusion is guided to the development. The image forming apparatus according to any one of claims 6 or 8, wherein the guide is guided to the first guide portion of the guide. The image according to any one of claims 1 to 9, wherein the developing agent carrier and the image carrier are in contact with each other when the drum cartridge and the developing cartridge are in the image forming position. Forming device. The invention according to any one of claims 1 to 9, wherein the developing agent carrier and the image carrier are in a non-contact state when the drum cartridge and the developing cartridge are in the image forming position. Image forming device.

Images